Support / FAQ

Before you look any further, make sure that you are running the latest version of PTGui. The current version is 12.24. See the version history for possible bugs that have been fixed in recent versions. Licensed users can upgrade at a reduced price, or free of charge, depending on the date of the original license purchase.

Documentation and Tutorials

The Video Tutorial on this site should help you get started using PTGui. Tutorials for advanced usage of PTGui can be found on the Tutorials page. And the Links page contains links to more tutorials, written by users of PTGui.

Detailed documentation for every feature and parameter is included with PTGui: in PTGui choose 'Help -> Help for this tab'.

Getting support

If you have a question or problem please first check the list of frequently asked questions below. The answer to your question may already be listed here.

If this does not solve the problem, post your technical support questions to the PTGui Support Forum. You will quickly get an answer from the PTGui authors or from other users.

Contact us

For non-technical questions (e.g. related to purchasing, downloading, software activation) please contact us directly at support at ptgui dotcom. Technical support questions should be posted to the PTGui Support Forum.

Frequently asked questions

1. Purchasing

1.1. I paid for a PTGui or PTGui Pro license but I haven't heard back from you!
1.2. I have purchased a PTGui license a couple of years ago. Do you offer discounted upgrade pricing?
1.3. I am a licensed user of PTGui; can I upgrade to PTGui Pro?
1.4. Which version should I purchase, PTGui or PTGui Pro?
1.5. Where can I find the license conditions for PTGui / PTGui Pro?
1.6. Do you offer special student pricing?
1.7. My organization needs a formal quote, or a pro forma invoice before we can purchase a license. Can you arrange this?
1.8. Can I still download older PTGui versions?
1.9. Can I install PTGui on both my PC and my laptop?
1.10. What is your upgrade policy?
1.11. How does the subscription license work?
1.12. Does my subscription automatically renew?
1.13. Do you also offer monthly subscriptions?
1.14. Do you offer subscriptions for the personal license?
1.15. Can I purchase a perpetual floating license?
2. Activation

2.1. I tried to enter my license key, but it doesn't work
2.2. How does activation work?
2.3. How does the floating license work?
2.4. For the floating license, what happens if the computer crashes or goes offline while PTGui is running?
2.5. Can we use an on-premise license management server to manage the floating license?
2.6. My computer is not connected to internet. Can I use PTGui?
2.7. What about hardware modifications?
2.8. My computer died / was stolen. How can I deactivate my license?
2.9. How can I transfer my license to another computer?
2.10. On how many computers is my license activated?
2.11. I lost my license key
2.12. I'm planning to switch from a PC to a Mac, is that possible?
2.13. We are running PTGui on multiple computers in a network environment. How can we deploy PTGui without activating each computer manually?
2.14. PTGui says 'failed to activate your license'. How can I resolve this?
2.15. Out internet connection is behind a proxy server. How can we activate PTGui?
2.16. Can a license be activated for all users on a computer?
2.17. Our network does not have internet access but we want to use the floating license. How can we set up a proxy server so that PTGui can be activated?
3. General questions

3.1. Is PTGui or the documentation available in other languages?
3.2. My lens database is empty, is that normal?
3.3. Can PTGui work with 16-bit images from start to finish (ie, no 8-bit conversion)?
3.4. Can I use PTGui to create virtual tours?
3.5. Sensor sizes: millimeters vs inches?
3.6. My images were taken with a (e.g.) 28mm lens, but after optimization, PTGui reports it as a 31.5mm lens
3.7. Can PTGui read RAW/DNG files?
3.8. Will PTGui read RAW files from camera XXX?
3.9. What does 'Apply Template' do?
3.10. Apply Template does not copy the control points from the template. Why is that?
3.11. What kind of computer hardware do you recommend for use with PTGui?
3.12. Does PTGui preserve the metadata of my images?
3.13. Can I stitch images from a shift lens with PTGui?
3.14. Where does PTGui store its settings?
3.15. PTGui doesn't fully use my computer's processor(s); the CPU load is less than 100% during stitching
3.16. After optimizing, PTGui shows me the average control point distance. What distance should I aim for?
3.17. Why does PTGui Pro close my project and open a new blank project after I press Save and Send to Batch Stitcher?
3.18. PTGui asks me whether I would like to re-initialize the project. What does this mean?
3.19. Can PTGui create those interactive photos where the camera is rotated around the object?
3.20. After stitching a project in the PTGui Pro Batch Stitcher, the project is modified!
3.21. I have edited my RAW / DNG files in Photoshop or another application. Does PTGui recognize my changes when I use the raw files in PTGui?
3.22. What can I do to reduce the stitching time PTGui on my system?
3.23. I have moved or rotated images in the Panorama Editor by hand using the Edit Individual Images mode. But PTGui tells me it needs to optimize the panorama and this undoes my changes. Why?
3.24. Can PTGui stitch greyscale images?
3.25. PTGui keeps changing the output size in the Create Panorama tab. Why?
3.26. How does PTGui calculate the optimum output size of a panorama?
3.27. Why does PTGui 11 use a different optimum size than PTGui 10?
3.28. What exactly does the Fisheye Factor parameter do?
3.29. Can I install different versions of PTGui side by side?
3.30. I've upgraded from PTGui 11 to PTGui 12 and now my panoramas look different.
3.31. I've upgraded from PTGui 11 to PTGui 12 but stitching is much slower now!
3.32. Does PTGui use cube faces internally as part of the stitching process?
3.33. What kind of tiles does the PTGui Viewer use internally?
3.34. When was PTGui first released?
4. Troubleshooting

4.1. I am trying to edit the seams of a layered panorama in Photoshop, but I only see the bottom layer with the merged panorama; the other layers are transparent.
4.2. Another application crashes when opening TIFF files generated by PTGui, or it displays garbled images.
4.3. My computer crashed while PTGui is running
4.4. PTGui shows a message 'PTGui was unable to detect control points for some of the images, therefore you need to add a few control points by hand'. Help! What should I do now?
4.5. PTGui is randomly rotating my images!
4.6. I'm having trouble stitching my panorama. Can you help?
4.7. After editing a 360 degree panorama in Photoshop and importing back into PTGui, I'm seeing a vertical line in the panorama
4.8. When installing on a Mac I get the error "PTGui Pro cannot be opened because the identity of the developer cannot be confirmed. macOS cannot verify that this app is free from malware."
4.9. I'm unable to open a QuickTime VR .mov panorama
4.10. I'm attempting to stitch images taken with multiple cameras but I'm running into stitching errors
4.11. My panoramas stitched using a template in the Batch Builder have misalignments. This only happens in the Batch Builder; the panorama is perfect if I use the same template in the GUI.
4.12. The Batch Builder seems to ignore the settings in my template; my panoramas come out different than expected.
4.13. The panorama in the PTGui Viewer is full of black dots!
4.14. I'm using PTGui 10; the stitching process hangs and never completes.
4.15. Panoramas published using Publish to Website are not displayed correctly using Firefox, the image is flashing.
4.16. The brightness or contrast in the Detail Viewer differs from the stitched panorama!
4.17. I'm getting an error message "These images cannot be linked because they have different dimensions. Linked images should have the same pixel dimensions." Why?
4.18. One of the source images is not included in the blended panorama. Why is that?
4.19. The image in the Detail Viewer looks different from the final panorama. I'm using exposure fusion / tone mapping.
4.20. PTGui is dislaying OpenCL errors, or the computer crashes while running PTGui on a Windows computer with NVIDIA graphics.
4.21. In Finder on my mac, all raw files are listed as type 'PTGui RAW'
4.22. I'm trying to level the panorama by dragging in the panorama editor. The panorama only moves; the curvature doesn't change.
4.23. PTGui reports 'failed to initialize OpenCL'
5. Improving the results

5.1. The horizon of my panorama is curved instead of straight
5.2. I get color/brightness differences between the images in my panorama
5.3. How can I change the resolution (ppi or dpi value) of the generated panorama?
5.4. I see misalignments in the stitched panorama. What can I do to improve the result?
5.5. Some control points in my project have a relatively high control point distance. Will the alignment of my panorama improve if I delete all control points with an error above a certain threshold?
5.6. My drone panoramas are showing misalignments at the horizon. How can I get a straight horizon?
6. How to...

6.1. My panorama contains curved lines. How do I get straight lines to remain straight in the panorama?
6.2. How do I use the Horizontal line and Vertical line control points?
6.3. How can I calibrate my lens parameters?
6.4. Does PTgui allow stitching of photos that have the camera in different locations?
6.5. How can I stitch mosaics, like partial scans from a flatbad scanner of a large image?
6.6. My panorama was taken with the camera tilted up or down. Now there's a lot of unnecessary black space above/below the panorama, increasing the size of the output. Can it be cropped away before stitching?
6.7. How can I have better control of the overlap area (i.e. the location of the seams)?
6.8. How can I create a vertical panorama? PTGui rotates my panorama 90 degrees!
6.9. I want to cover the tripod in my (360x180 degree) spherical panorama. How do I add a nadir cap?
6.10. How can I change the default settings for new panoramas?
6.11. How can I stitch extremely large panoramas?
6.12. How can I align a set of images, all taken in the same direction (not a panorama)?
6.13. How can I use exactly the same stitching settings for different sets of images?
6.14. How can I correct a single image for lens distortion?
6.15. How can I show a panorama on my website?
6.16. How can I publish a panorama to Facebook?
6.17. Why does Facebook display my panorama as a flat image, not as an interactive panorama?
6.18. How can I use PTGui to add the metadata required by Facebook to an already stitched panorama?
6.19. How do I level/straighten a panorama using horizontal / vertical line control points?
6.20. How can I correct a single image for vignetting in PTGui Pro?
6.21. My spherical panorama still has a hole in the top and/or bottom. How do I fill the missing parts to make the panorama truly spherical?
6.22. After running Publish to Website my panorama has black holes at the top and bottom; how do I get rid of these?
6.23. PTGui leaves some blank space around my panorama. How can I crop the panorama so that it fills the canvas entirely?
6.24. How can I tell PTGui to output panoramas at a specific size?
6.25. How can I defish a fisheye image in PTGui?
6.26. How can I extract a 'flat' image from a spherical panorama?
6.27. I have taken multiple panoramas from the same viewpoint, to create a time lapse movie. How can I ensure that subsequent panoramas are aligned when played back in sequence?
6.28. My project contains one or more images without any recognizable detail and it's impossible to place control points. How can I stitch my panorama?
6.29. How can I view a finished panorama interactively on my computer?
6.30. I would like to send a panorama to a friend/client/... Is it possible to view a panorama interactively without needing to install a plugin first?
6.31. I need to align/overlay an image to an already stitched panorama. How can I do this?
6.32. How can I stitch a PTGui project from the command line?
6.33. Can I use PTGui to arrange pictures into a collage? Can I disable the warping/distorting of images?
6.34. How can I stitch panoramic video in PTGui?
6.35. Is there a way to stitch many panoramas using the same settings?
6.36. How can I make 'little planet' images in PTGui?
6.37. How can I stitch images from Adobe Lightroom in PTGui? Do you offer a Lightroom plugin?
6.38. Can you tell me how to make 3d (stereoscopic) panoramas in PTGui?
6.39. How can I stitch two back-to-back circular fisheye images?
6.40. How can I retouch the nadir of a spherical panorama?
6.41. How can I stitch images taken with a 360° one shot camera in PTGui?
6.42. How can I prevent PTGui from placing control points in certain areas?
6.43. We are trying to parse a PTGui .pts project file. Can you explain how the lens parameters are stored?
6.44. How can I rotate individual images? The rotation buttons in the Project Assistant tab only seem to rotate all images together.
6.45. I have 6 cube face images. How can I combine them into a panorama?
6.46. How can I align a panorama against a reference image?
7. PTGui Pro and HDR

7.1. What is the best way to take images for HDR stitching in PTGui Pro?
7.2. My images don't contain EXIF exposure information. Can I still use them to stitch HDR panoramas?
7.3. PTGui Pro doesn't recognize my bracketed exposures!
7.4. PTGui Pro displays the wrong EV values! My images were taken at -2, 0, +2. This is confirmed by the EXIF data but PTGui shows something else in the Image Parameters tab.
7.5. What does linking images do?
7.6. Can I retouch an HDR panorama, e.g. to remove ghost images of moving people?
7.7. I would like to stitch my panorama in PTGui Pro, but use another application (e.g. Photomatix or Photoshop) to create the HDR.
7.8. Can I use PTGui Pro for exposure fusing / tone mapping / HDR generation of non-panoramic images?
7.9. Can I extract artificial bracketed images from my (non bracketed) RAW files and have PTGui Pro assemble those into an HDR panorama?
7.10. I have read the previous answer but I still would like to stitch my pseudo bracketed images generated from RAW files!
7.11. The brightness or contrast in the Detail Viewer differs from the stitched panorama!
8. GPU acceleration

8.1. Which GPUs are supported by PTGui?
8.2. Which graphics card should I buy?
8.3. Does PTGui support using multiple GPUs?
8.4. PTGui reports 'no supported GPU device available' even though my (Windows) computer has an NVIDIA GPU supporting OpenCL.
1. Purchasing

1.1. I paid for a PTGui or PTGui Pro license but I haven't heard back from you!
We send you your license key as soon as possible after receipt of your payment. Occasionally this may take up to 24 hours, but we always send an order confirmation email immediately after completing the order process. So if you don't hear from us shortly after completing your order, this means that our email has failed to reach you. Unfortunately this happens occasionally, usually due to spam filter problems or a full mailbox.

If your mailbox has a Junk Mail folder, look for mail from PTGui Support <support@ptgui.com>. Many junk mail filters have a white list feature (often called 'trusted senders'); please add our address to it.

Then login to your account (with the email address used for purchasing) to retrieve your license key and invoice. To login we'll send you an access code by email; if you still don't receive our mails please contact us at contact us at support at ptgui dotcom. If possible, contact us from a different email address (at a different domain), otherwise our reply may suffer from the same email delivery problem.
1.2. I have purchased a PTGui license a couple of years ago. Do you offer discounted upgrade pricing?
Every PTGui and PTGui Pro license comes with one year of free upgrades. After that year you can upgrade your license at by paying an upgrade fee. Your upgrade purchase will include another year of free upgrades. See Upgrade pricing for more information. See Version History for what's new in the latest version.
1.3. I am a licensed user of PTGui; can I upgrade to PTGui Pro?
Yes this is possible. If you upgrade to Pro within one year, you just need to pay the (current) price difference between the two versions. See Upgrade pricing for more information.
1.4. Which version should I purchase, PTGui or PTGui Pro?
See Features of PTGui and PTGui Pro for a comparison of the two versions. Separate trial versions are available for PTGui and PTGui Pro, so you can try both. If you're not sure whether you need the Pro version, consider purchasing a license for the standard version first. Within one year you will be able to upgrade to PTGui Pro by paying the (current) price difference between the two versions.
1.5. Where can I find the license conditions for PTGui / PTGui Pro?
See: End User License Agreement
1.6. Do you offer special student pricing?
No, we do not offer educational or any other kind of discounts on individual license purchases. We do offer discounted company licenses to universities and schools (2 seats minimum), please contact us for details.
1.7. My organization needs a formal quote, or a pro forma invoice before we can purchase a license. Can you arrange this?
Yes, this is possible: proceed with ordering your license. On the checkout page choose: 'Payment Method: Bank transfer (with pro forma invoice)'. We'll send you a PDF pro forma invoice by email. The pro forma invoice also serves as a formal price quote. The actual purchase can be made by international bank transfer but also by credit card or PayPal. Payment instructions are included in the email. The pro forma invoice is non binding, you can cancel your order at any time (by not paying). Please understand that we do not accept purchase orders, nor can we agree to any kind of purchase terms or conditions.
1.8. Can I still download older PTGui versions?
Yes, many older versions of PTGui and PTGui Pro are still available for download by licensed users. See the Downloads archive.

On macOS you may need to bypass Apple's security restrictions (see Q4.8).
1.9. Can I install PTGui on both my PC and my laptop?
A personal license may be activated on up to two computers simultaneously, but only for personal use by the licensed person. If other people wish to use PTGui, multiple personal licenses or a company license should be purchased instead.

The company license is purchased for a certain number of computers. PTGui can be activated simultaneously on this maximum number of computers.

The floating license is purchased for a number of simultaneous users. It can be installed on many computers, only the number of concurrent users is limited.

Conditions apply; see the End User License Agreement for details.
1.10. What is your upgrade policy?
Every (perpetual) license comes with one year of free upgrades. In addition to this, we will continue to offer all minor version updates for your licensed version free of charge even after one year. In other words, if you purchase a license at the time when PTGui 11 is available, all 11.x updates will be included. If PTGui 12 gets released within one year, you will be able to upgrade free of charge and also get all 12.x updates.

To any major version released after more than one year, you can upgrade for a fee (see Upgrade pricing). Upgrading is voluntary, you will be able to continue using your licensed version forever.

The above applies to the perpetual licenses (including the personal license). The subscription license is different: you will have access to the latest version of PTGui for as long as your subscription is running.
1.11. How does the subscription license work?
For the company license we offer a yearly subscription option. This always gives access to the latest version of PTGui for the duration of the subscription, at lower up front cost than the perpetual license.

At the end of the license term you can renew your license by paying for the next year. Automatic renewal is also possible, but we will do this only if you opt in.

All your files are stored on your computer and you can of course continue to access your images even after the license has expired.
1.12. Does my subscription automatically renew?
The perpetual license and the personal license don't need to be renewed, it's a one-time payment.

For the company and floating subscription licenses we offer an automatic renewal option for your convenience, but this is entirely optional. We don't want anyone to continue paying for a subscription they don't want anymore.

If you don't check the automatic renewal box on the order form (and it's not selected by default), we will only bill you once. Near the end of the subscription we will send you a reminder email to let you know that your subscription is about to expire. If automatic renewal is enabled, we will then charge your card for the next term at the moment your subscription expires. Otherwise, you can renew manually in your account, or start a new subscription at a later time.

If you have automatic renewal enabled, you can disable it at any time in your account.
1.13. Do you also offer monthly subscriptions?
No, for the time being the only subscription option is a yearly subscription. We may offer monthly subscriptions in the future.
1.14. Do you offer subscriptions for the personal license?
No, at this time we only offer subscriptions for the company license. You can purchase a company license subscription though.
1.15. Can I purchase a perpetual floating license?
No, the floating license is available only in subscription form.
2. Activation

2.1. I tried to enter my license key, but it doesn't work
The license key is quite long and it is easy to make mistakes. Therefore please copy/paste the key from the original order confirmation email. Select the code and press Ctrl+C, then paste into PTGui using Ctrl+V. On mac use Cmd+C and Cmd+V instead. If you don't have the license key anymore, login to your account to retrieve it. Be sure to login with the email address used for purchasing the license.

A license key purchased before September 2021 would look like this:
NERpcSh*/RyE3LUGHWcM7FMSPX8Fu+4HSRkdufrbw2gRtW3K#8puU+baLz4Q
5SupUTuDBTyiWhQjQqLCah#9tDTm7SNQsE9n!UvhJhy3KdH6HgJ+d2EE2x==

Keys purchased from September 2021 have a shorter format:
X7AXW-ZDVSN-5FAMB-A6XF2-1GJ91
2.2. How does activation work?
When you run PTGui for the first time on your computer it will ask you for your license key. This license key together with your computer's hardware configuration is sent to our servers. Assuming the permitted total number of installations is not exceeded, we will then activate your license on this particular computer.

A personal license may be activated on 2 computers simultaneously, but only for personal use by the licensed person.

A company license is purchased for a certain number of seats. It can be activated on this number of computers.

If you move PTGui to a different computer, deactivate the old machine via Help - License Info - Deactivate. This releases the seat and makes it available for use on another computer. If you can no longer access the computer, go to your account and request us to deactivate your computer. Deactivation may incur a processing time of up to 24 hours.

A license may be deactivated and reactivated as often as needed. However to prevent abuse of the deactivation facility, PTGui is required to verify the activation status at least once every 30 days. If an internet connection is available, this happens automatically while PTGui is running. Otherwise, offline activation must be repeated manually every 30 days.

The floating license is handled differently: the same license can be installed on many computers; only the number of computers that can run PTGui concurrently is limited. See Q2.3.

Other conditions apply; see the End User License Agreement for details.
2.3. How does the floating license work?
When the user launches PTGui, it will contact our license servers and check if any seat of the configured license is available. If so, PTGui will start and it will hold on to the license seat for as long as it is running. To do so it must be able to stay in contact with the license servers, so an internet connection is required all the time. When the user closes PTGui, the license seat will be released and instantly become available for use on another computer.
2.4. For the floating license, what happens if the computer crashes or goes offline while PTGui is running?
Short network disruptions should not cause any problems. But if there is no network connection when closing PTGui, or if the computer crashes, the license seat will not get released. To fix this, when the computer is online again, restart PTGui and quit it immediately. This will release the license seat right away. Otherwise, the seat will become available again for use on other computers after a short time (currently 60 minutes).
2.5. Can we use an on-premise license management server to manage the floating license?
No, the license management is handled by our cloud-based license servers. PTGui needs to be able to contact the license servers while running. If internet access in your network is restricted, we do support a proxy server which can act as a gateway to the license servers. See Q2.15. Setting up a proxy server specifically for activating PTGui is simple; see Q2.17.
2.6. My computer is not connected to internet. Can I use PTGui?
For the personal and the regular (per-computer) company license: yes, offline use is supported. The floating license requires a network connection all the time though.

To activate the computer with the personal or the regular company license, a network connection is required. If the computer running PTGui is not connected to Internet, it can still be activated using another computer with internet connection. Select Activate Offline to do so. This generates a code which is to be entered on a web page. The web page returns another code which can be entered in PTGui to complete the activation. You can transfer the codes between the computers using an USB drive for example.

Computers may be deactivated and reactivated as often as needed. However to prevent abuse of the deactivation facility, PTGui is required to verify the activation status at least once every 30 days. This means that if no internet connection is available, offline activation must be repeated every 30 days.
2.7. What about hardware modifications?
Activation is not affected by small upgrades, like adding more memory. But larger upgrades may cause PTGui to consider the computer to be a different machine and ask for a new activation. Before performing a hardware upgrade it is therefore best to deactivate the license via Help - License Info - Deactivate. When you launch PTGui again after the upgrade, use the original license key to reactivate.

If you forgot to deactivate, you can request deactivation of your old hardware from your account, though processing may take up to 24 hours in this case.
2.8. My computer died / was stolen. How can I deactivate my license?
If you can no longer access the computer please go to your account and request us to deactivate your computer. Deactivation may incur a processing time of up to 24 hours. We will notify you by email when the license is available again for use on another computer.
2.9. How can I transfer my license to another computer?
For PTGui 11 and later: On the old computer, go to Help | License Info and press Deactivate. Now the license key can be used to install PTGui on the new computer. If you can no longer access the computer please go to your account and request us to deactivate your computer (but note that this may take up to 24 hours).

PTGui 10 and earlier can be deactivated by going to the About window, press Register and then press the Deactivate button. On Windows, 'About' can be found in the Help menu; on macOS it's in the 'PTGui [Pro]' menu.
2.10. On how many computers is my license activated?
Go to your account and login with your license key to see the currently activated computers.
2.11. I lost my license key
No problem; you can retrieve the license key in your account. Be sure to login with the email address used for purchasing the license.
2.12. I'm planning to switch from a PC to a Mac, is that possible?
No problem, the same license can be used on Windows, macOS and Linux. You will be able to transfer the license to another computer.
2.13. We are running PTGui on multiple computers in a network environment. How can we deploy PTGui without activating each computer manually?
Each computer running PTGui must be activated. The activation process keeps track of the number of computers on which a PTGui license is used. Normally PTGui will ask for the license key to activate the software when it is run for the first time on a computer. This step can be automated by installing a provisioning file containing the license key. If such a provisioning file is present, the user does not have to enter the license key and PTGui will be activated automatically when it is run for the first time on a computer, using a license key from the provisioning file.

The provisioning file must be stored in this location on Windows computers:
C:\ProgramData\PTGui\licensekey.json
On macOS:
/Users/Shared/Application Support/PTGui/licensekey.json
On Linux:
/etc/PTGui/licensekey.json

licensekey.json is a JSON file with the following structure:
{
  "licensekeys": [
    {
      "regkey": "PSPGS-N14MN-R11B5-4N29E-EATR4"
    },
    {
      "regkey": "SEM2K-JXS9N-6D5RW-975VQ-E7ARJ"
    }
  ],
  "asklicensekey": false
}

If a proxy server is required for internet access, a "proxy" section can be added as follows:
{
  "licensekeys": [
    {
      "regkey": "SEM2K-JXS9N-6D5RW-975VQ-E7ARJ"
    }
  ],
  "proxy": {
    "url": "http://ip.address.of.proxy:8888",
    "user": "userNameForProxy",
    "password": "secretPassword"
  },
  "asklicensekey": false
}

If the "proxy" section is missing in the .json file, existing proxy settings (if any) in the PTGui configuration will still be used. The proxy settings can be edited in Options - Advanced. If the proxy settings are included in the .json file, the settings in the PTGui configuration will be updated the next time PTGui is launched. Include an empty proxy section to remove a configured proxy server:
"proxy": {}

The file can contain multiple license keys (2 in the first example above); PTGui will attempt to activate using the keys in this order. If a key is already activated on another computer, the next key will be used, until activation is succesful.

Note that older PTGui license keys consist of two lines, but strings in JSON must be represented in a single line. PTGui ignores line endings in the license key, so the two lines of the license key can simply be concatenated into a single line. You can validate the syntax of your JSON file using (e.g.) JSONLint.

If activation fails, the behavior depends on the field 'asklicensekey'. If set to false (the default), when activation fails, PTGui displays an error message and quits. If set to true, the user will be given the opportunity to enter a different license key to activate PTGui. If activation with the user provided key is successful, licensekey.json will be ignored in the future (until the next time activation fails). The 'asklicensekey' field was added in PTGui 12.15; previous versions behaved as if asklicensekey was set to true.

To install PTGui on multiple Windows computers in the network you can script your deployment system to run the PTGui installer in silent mode as follows (replace PTGuiSetup.exe with the actual file name of the installer):
PTGuiSetup.exe /S /D=C:\Program Files\PTGui
Note that the options are case sensitive, so use a capital /S and /D. The installer can be run without uninstalling a previous version first.

On a Mac no installation is necessary, just copy the PTGui application bundle into the Applications folder.

On Linux, extract the files from the PTGui archive in a desired location. Use the provided install.sh script to create desktop entries.

A license can be deactivated on a computer as usual, through Help - License Info - Deactivate from within PTGui on the licensed computer. If this is not possible, remote deactivation can be requested from your account. Be sure to remove licensekey.json after deactivation, otherwise PTGui will be reactivated automatically and silently when it is launched again.

For activation PTGui needs to be able to contact the activation server (see Q2.14).
2.14. PTGui says 'failed to activate your license'. How can I resolve this?
To activate your license on your computer PTGui needs to contact the license server. This may fail if there is no internet connection or if the computer is behind a corporate firewall.

If there is a firewall, it should be configured to permit outgoing network connections to activation1.ptgui.com and activation2.ptgui.com on TCP port 443. If necessary PTGui can use a proxy server to access the internet (see Q2.15).

If internet access is not available or restricted, PTGui offers an offline activation option: in the activation window press the Activate Offline button and follow the instructions. Please note that offline activation is not possible for the floating license.
2.15. Out internet connection is behind a proxy server. How can we activate PTGui?
A proxy server can be configured in PTGui by pressing the Proxy button in the activation window, or in Options / Preferences - Advanced. Enter the URL of the proxy server, including the protocol and port number. For example:

http://proxy.example.com:8888 (HTTP proxy)
socks5://proxy.example.com:1080 (SOCKS proxy)

The proxy server should be able to forward HTTPS requests to activation1.ptgui.com and activation2.ptgui.com on port 443. An HTTP proxy server should support the CONNECT keyword for HTTPS connections.

Setting up a proxy server specifically for activating PTGui is simple; see Q2.17.
2.16. Can a license be activated for all users on a computer?
A personal license is licensed to a single person; only this person is permitted to use PTGui. For this reason a personal license is activated for a single user account on the computer only. For more information see Q1.5.

A company license is licensed per computer, and PTGui may be used by any person on that computer. Therefore the company license can be activated for all users on a computer.

To do so, ensure that all users have read and write permissions to this folder:
C:\ProgramData\PTGui\
(Windows) or
/Users/Shared/Application Support/PTGui/
(macOS). Activation data will be stored in a file named reg.dat in this folder. When activating PTGui with a company license key, and the above folder can be written to, PTGui will ask whether the license should be activated for all users on the computer. Answer Yes to do so. If PTGui was already activated for a single user, first deactivate the software via Help - License Info - Deactivate. Then re-activate the software by entering the license key after ensuring all users have write permissions to the above folder.
2.17. Our network does not have internet access but we want to use the floating license. How can we set up a proxy server so that PTGui can be activated?
PTGui can use a proxy server to contact the activation server. The open source 'squid' software can be used to setup a proxy server on Linux. The proxy server itself must be able to access the license servers on the internet, but the PTGui installations in the network just needs to contact the local proxy server. The proxy can be restricted so that it only allows access to the PTGui license server and nothing else.

Install squid:
yum install squid  # on fedora, redhat, cenos, rocky linux
apt install squid  # on debian, ubuntu, mint

Create the file /etc/squid/conf.d/ptgui.conf with the following content:
# proxy listening port:
http_port 8760
#
# Allow connections to https://activation1.ptgui.com:443 and https://activation2.ptgui.com:443
acl whitelist dstdomain activation1.ptgui.com activation2.ptgui.com
acl http proto http
acl port_443 port 443
acl CONNECT method CONNECT
http_access allow CONNECT port_443 whitelist
#
# And deny everything else:
http_access deny all
# Additional configuration may be needed; see: http://www.squid-cache.org/

Then restart squid:
systemctl restart squid
systemctl enable squid

In PTGui, go to Options - Advanced - Proxy. Configure the proxy server as:
Proxy URL: http://<ip address of proxy>:8760
The proxy username and password can be left empty.

The proxy settings in PTGui can be provisioned automatically through a licensekey.json file. See Q2.13.
3. General questions

3.1. Is PTGui or the documentation available in other languages?
Yes, PTGui and its documentation are available in English, Deutsch, Nederlands, Español, Français, Português, 日本語, 한국어 and 中文. The language can be selected in Options/Preferences.
3.2. My lens database is empty, is that normal?
Yes, it is. You can use it to store your optimized lens data.
3.3. Can PTGui work with 16-bit images from start to finish (ie, no 8-bit conversion)?
Yes, PTGui performs all image processing in 16 bit if a 16 bit output format is selected on the Create Panorama tab. PTGui Pro even supports 32 bit floating point images.
3.4. Can I use PTGui to create virtual tours?
PTGui includes a viewer for publishing panoramas on a website. See Q6.15 for more information.

The web viewer included with PTGui is just a basic viewer for publishing individual panoramas. For a true virtual tour consisting of multiple panoramas linked by hotspots, clickable floor plans, etc, dedicated panorama publishing software exists. All panorama publishing software can load panoramas in 360 x 180 degree equirectangular projection, as created by PTGui. See Q6.15 for software recommendations.
3.5. Sensor sizes: millimeters vs inches?
To determine the lens projection, PTGui needs to know the dimensions (in millimeters) of the camera's sensor. Some manufacturers state the sensor size in fractions of an inch (e.g. 1/2.5"). The inch-designation dates back to TV camera tubes in the 50s and it does not appear to be mathematically related to the actual sensor size. See Table of sensor formats and sizes (Wikipedia) for a conversion table.
3.6. My images were taken with a (e.g.) 28mm lens, but after optimization, PTGui reports it as a 31.5mm lens
This is normal; the optimizer adjusts your project in such a way that the lowest control point distance is obtained. By default this involves modifying the focal length of the lens. Apparently it is at this focal length that PTGui achieves the best alignment of the images.
3.7. Can PTGui read RAW/DNG files?
Yes, PTGui uses LibRaw which allows it to read RAW files produced by many cameras.

Note that RAW files are not regular image files. The RAW file records the data straight from the camera's sensor, which needs to be demosaiced and processed further before it can be used. Therefore RAW files should rather be seen as a digital 'negative' which first needs to be developed to get the actual image.

This development is done using standard settings, although PTGui Pro does allow you to adjust exposure and white balance in the HDR/Exposure tab.

If you need more control, use a dedicated RAW converter instead and save the converted RAW files as 16 bit TIFF images. The TIFF files can then be loaded into PTGui. This preserves the image quality and full dynamic range of the source images. Be sure to convert all source images in a panorama using the same settings, otherwise color or brightness differences may remain visible in the panorama.

Also, any adjustments made to the RAW file in Photoshop RAW (or other RAW converters) are ignored by PTGui. These programs do not actually change the RAW file; instead they write the modifications to a so-called sidecar (.xmp) file. The sidecar file contains closed proprietary data and cannot be read by other software. Therefore, if you need to make changes to RAW file or need finer control over the conversion, use a dedicated raw converter and save the images to 16 bit TIFF format.

Finally, since all RAW files are different it's possible that LibRaw does not (yet) support your camera. In that case it's also necessary to convert your images to TIFF before loading them into PTGui.
3.8. Will PTGui read RAW files from camera XXX?
PTGui uses the open source LibRaw library for decoding raw files. See Supported Cameras on the LibRaw website for a list of cameras supported by LibRaw, or try loading your images in the free trial version.

PTGui can only read raw files supported by LibRaw. If LibRaw does not support your camera, use a dedicated raw converter to convert the images to 16 bit TIFF.

See Q3.7 for more information.
3.9. What does 'Apply Template' do?
This copies the settings of another project to the current project, except for the images and the control points. This function is accessible both from the 'Apply Template' item in the File menu, and from the toolbar in PTGui. A template can be any PTGui project. In Tools/Options/Folders&Files, a folder can be configured where you store your templates (on Mac go to the PTGui menu, Preferences, Folders&Files). The template selection dialog will by default open in this folder. The 'Apply Template' button on the toolbar shows a drop down list of all templates in the configured template directory, for quick access.

Templates can be useful for a quick initialization of a project (lens settings, rough alignment of images), although this is usually not necessary since the Project Assistant can figure out the alignment of the panorama by itself.

Another use for templates is when you have an exact reproducable setup (high quality panoramic head with fixed angles). In this case you could copy all settings of a previous project and there would be no need for placing control points and optimizing.

By default, applying a template copies all settings from the template to the current project except for the source images and the control points. In PTGui Pro this behavior can be modified in the Project Settings tab, section 'template behavior'.
3.10. Apply Template does not copy the control points from the template. Why is that?
By default applying a template copies all settings from the template except for the actual source images and the control points (see Q3.9). Control points are never copied since they are specific to the source images. For example a control point could originally point to the corner of a building in the template project, but in another project the same coordinates may be in the middle of plain blue sky. In other words the control points are meaningless outside the context of the original images.

If you just need a project to be stitched exactly like the template project, control points are not needed at all. Control points are only used by the optimizer to determine the best image parameters. The stitcher only uses the optimized image parameters and ignores the control points. Therefore it's sufficient to apply the template (which copies the image parameters) and proceed straight to Create Panorama without running the optimizer.
3.11. What kind of computer hardware do you recommend for use with PTGui?
PTGui does not require any special hardware, even for stitching large panoramas. But if you're looking for high performance we recommend a PC with the following specifications:
3.12. Does PTGui preserve the metadata of my images?
Currently, the following metadata is copied to the generated panorama: For HDR panoramas in PTGui Pro, the 'blend planes' output contains the exposure/iso/aperture of that particular exposure, for merging in external software.

Other EXIF data is currently not copied to the output file. The above metadata is written to JPEG, TIFF, psd and psb images. For .hdr no metadata is written. The .exr format does not support EXIF or XMP metadata and PTGui only includes the exposure information. The color profile is read and written in the .exr specific 'chromaticities' tag. But note that this is not widely supported. Many other applications (including Photoshop) ignore this entirely, and assume all .exr files have a linear sRgb color profile.
3.13. Can I stitch images from a shift lens with PTGui?
First of all, you don't need a shift lens if you have PTGui! Shift lenses are often used for architectural photographs: photographing a building from ground level, while tilting the camera upwards, normally results in converging vertical lines. Shift lenses compensate for this effect by shifting the optical axis of the lens relative to the center of the image plane. The result is a photograph where parallel lines remain parallel.

The same effect can be achieved in PTGui: open the Panorama Editor window, press Ctrl-P to switch to 'Panorama Edit' mode. Now drag the panorama upwards or downwards until parallel lines in the scene are parallel in the panorama. You may need to increase the vertical field of view (using the slider to the right of the panorama).

If you do want to stitch images taken with a shift lens in PTGui, change the following parameters: Regardless whether a shift lens is used, or the panorama was shifted in the Panorama Editor, you will end up with some black space below or above the panorama. This can be removed by dragging yellow crop lines from the edges of the panorama in the panorama editor. The process is shown in detail in part two of our Video Tutorial.
3.14. Where does PTGui store its settings?
PTGui stores its configuration data in this folder:

Windows:
%APPDATA%\PTGui\

macOS:
~/Library/Application Support/PTGui/

Linux:
$HOME/.PTGui/

To open this folder, do Tools - Open Folder - PTGui Configuration Folder in PTGui. Most configuration data is stored in Configuration.xml in this folder. The default folders for Templates and Batch Lists also reside here.
3.15. PTGui doesn't fully use my computer's processor(s); the CPU load is less than 100% during stitching
Stitching and blending requires a lot of disk and memory access. In particular for large panoramas, or on multi core computers, not the processor but the hard disk may be the speed limiting factor. Also, with a suitable graphics card much of the processing is offloaded to the GPU. If you are looking into increasing stitching speed, see Q3.11.
3.16. After optimizing, PTGui shows me the average control point distance. What distance should I aim for?
The control point distance indicates how well a control point pair aligns in the panorama. When the distance is zero, the two points of a control point pair overlap exactly.

One should aim for the lowest control point distance possible, but the actual lowest distance that can be achieved depends on many factors. In general if your images were shot properly using a tripod with calibrated panorama head, a control point distance well below 5 should be achievable. Most remaining misalignments can usually be masked by the blender. An average distance higher than 5 usually indicates a problem, see Q5.4 for solutions.

It's particularly important to look at 'outliers': if a control point has a distance of 20 while the average is below 5, this control point might have been placed on a moving object, or on a similar feature close to the proper location. Use the 'Delete worst control points' function (in the Control Points menu) to remove such outlying control points.
3.17. Why does PTGui Pro close my project and open a new blank project after I press Save and Send to Batch Stitcher?
The Batch Stitcher of PTGui Pro can generate control points; it will do so if instructed by the 'Do Align Images and save the modified project' checkbox in the Project Settings. By default this is enabled if the control point generator has not yet been run for the project. This allows you to quickly generate a panorama in batch: start a new project, load your source images and press Save and Send to Batch Stitcher. The batch stitcher generates control points and stitches the panorama in one go.

After generating control points and aligning the images the batch stitcher overwrites the project file with the modified version. Since the Batch Stitcher will modify the project file, problems could occur if the project would remain opened at the same time in the main PTGui Pro window: both instances would be writing to the same project file, discarding each other's changes.

For this reason, PTGui Pro will close the project after sending it to the batch stitcher if the Batch Stitcher is configured to modify the project. This ensures that only one instance of the project is open. A warning message is shown before the project is closed but the warning is no longer shown if 'don't show this again' had been selected. To re-enable the warning message, go to Options/Preferences and click 'Reset all warning messages'.

In previous version of PTGui, a temporary copy of the project would be sent to the batch stitcher. This functionality is still available through 'Send Temporary Copy to Batch Stitcher'. This creates a copy of the current state of the project in a temporary file, which is sent to the batch stitcher for stitching. When stitching has finished the temporary project file is deleted by the batch stitcher.
3.18. PTGui asks me whether I would like to re-initialize the project. What does this mean?
If PTGui fails to properly align your images, the following question may appear:

"The optimizer failed to achieve a good alignment of the images. Possibly the current misalignment of the images causes the optimizer to get stuck. Re-initialization of the project may help in such a case. Would you like to re-initialize the project and try to optimize again?"

If you click OK, PTGui will reset the yaw, roll and pitch of all images to zero and reinitialize the lens settings based on the EXIF data. Then it will attempt to figure out the image positions from scratch and subsequently reoptimize the project.

In particular in cases where the optimizer got stuck in a so-called local minimum such an initialization from scratch can be the solution.

This function can be triggered manually using the Initialize and Optimize (in the Project menu).
3.19. Can PTGui create those interactive photos where the camera is rotated around the object?
These are commonly called 'Object Movies'; they cannot be created through stitching and therefore PTGui does not support this. A software package for creating object movies is Object2VR.
3.20. After stitching a project in the PTGui Pro Batch Stitcher, the project is modified!
The batch stitcher of PTGui Pro can not only stitch projects, but it can also set up a new panorama project by generating control points, aligning the images, etc. It will do so if instructed by the 'Do Align Images and save the modified project' checkbox in the Project Settings tab. If the project or template is already set up completely and the panorama should only be stitched, make sure that the above checkbox is unchecked.
3.21. I have edited my RAW / DNG files in Photoshop or another application. Does PTGui recognize my changes when I use the raw files in PTGui?
No, PTGui will load the raw files as they came straight from the camera, any modifications are ignored. In Photoshop RAW files can be edited, but the changes are written to a 'side car' file (with the .xmp extension) rather than to the original raw file. The settings in the side car file are specific to the algorithms used by Photoshop and cannot be used by other applications.

To use the modified RAW files in PTGui, export them to 16 bit TIFF files and load those in PTGui instead. Since RAW files typically only have 12 or 14 bits per channel, the full dynamic range will be preserved by the 16 bit TIFF file, so there is no loss of quality.
3.22. What can I do to reduce the stitching time PTGui on my system?
The time required to stitch a panorama is influenced by many factors, such as the dimensions of the panorama, the computer hardware and by other applications running at the same time. Some general hints to improve the stitching performance:
3.23. I have moved or rotated images in the Panorama Editor by hand using the Edit Individual Images mode. But PTGui tells me it needs to optimize the panorama and this undoes my changes. Why?
Don't attempt to align images manually: it's impossible to get the required precision for a seamless stitch. Even if you would manage to accurately align an image to one neighbouring image, this would throw it out of alignment with its other neighbour images.

Instead, let the PTGui optimizer do all the hard work through control points. Control points tell PTGui which points of two images should overlap. By providing 3 or 4 control point for a pair of overlapping images, PTGui will know how they overlap and the optimizer will align the images with pixel accuracy.

For more information watch our our Video Tutorial.
3.24. Can PTGui stitch greyscale images?
PTGui was designed to efficiently stitch RGB color images (with or without transparency). It can read single channel greyscale TIFF files but the output will always be in RGB format. If you require single channel greyscale TIFF files as output, use third party software such as Photoshop to convert the output to the desired format.
3.25. PTGui keeps changing the output size in the Create Panorama tab. Why?
By default (the Create Panorama tab will show 'fix at 100% of optimum size'), PTGui will output your panorama at the so called Optimum Size. The optimum size is the output size at which the resolution of the panorama equals the resolution of the source images. For more information see Q3.26.

Because the optimum size depends on several parameters, including the focal length of the lens which is usually fine tuned by the optimizer, the optimum size may vary slightly after each optimization. This depends also on control point placement. If this fluctuation is unwanted, in the Create Panorama tab pick a desired size and select 'Fix at ... megapixels'. From now on PTGui will keep the number of pixels in the panorama constant.
3.26. How does PTGui calculate the optimum output size of a panorama?
The optimum size is the output size at which the resolution of the panorama equals the resolution of the source images. In other words, no detail from the source images is lost.

Because image warping is not uniform across the panorama, there is no true optimum size: some parts of the source images may get enlarged while other parts may be reduced in size. Therefore, somewhat arbitrarily, PTGui considers the optimum size to be the size where the angular resolution of the center of the source images equals the angular resolution of the center of the panorama. If images from multiple lenses are used, this calculation will be based on the source image having the highest resolution.

Because the optimum size depends on the focal length, and the focal length is adjusted by the optimizer after editing control points, the optimum size may vary slightly for different projects using the same lens. See Q3.25.

For a spherical equirectangular panorama the optimum size is calculated as follows:

Here, w is the calculated optimum width of a 360° equirectangular panorama, f is the lens focal length (in mm), rp is the source image width in pixels, rm is the sensor width in mm. This formula is applicable for both fisheye and rectilinear lenses. For example, an 8mm fisheye lens on a full frame 24 megapixel (6000 * 4000) camera gives an optimum width of 2*pi*8*6000/36 = 8378 pixels. So the 2:1 equirectangular image is 8378 x 4189 pixels, or 35 megapixels.

Or, in another form:

Here Ppano is the optimum panorama size in megapixels, f is the focal length, c is the crop factor (1 for full frame, 1.6 for APS-C) and Pcamera is the sensor size in megapixels. The sensor is assumed to have a 3:2 aspect ratio.

In other words: to get a higher resolution panorama, either use a longer focal length, or a smaller sensor (with the same number of pixels in a smaller surface). Also, the amount of overlap or the camera orientation will not affect the optimum size.
3.27. Why does PTGui 11 use a different optimum size than PTGui 10?
In PTGui 11 a new lens parameter, the 'fisheye factor' was introduced (see Q3.28). This allows it to perfectly model all practical fisheye projections. PTGui 10 didn't include this parameter and used equidistant projection for all fisheye images. The difference between the actual projection and equidistant projection was modeled using the lens distortion (a/b/c) coefficients. When calculating the optimum size, the lens distortion coefficients are not taken into account, resulting in an error in the calculated optimum size. PTGui 11 does take the fisheye factor into account when calculating the optimum size.

In other words, the optimum size is calculated more accurately in PTGui 11 than in PTGui 10. Regardless, it's still a somewhat arbitrary measure (see Q3.26) and it's possible to output at any desired size.
3.28. What exactly does the Fisheye Factor parameter do?
There is no single fisheye projection, different fisheye lenses exhibit different optical projections. For example, equidistant, equisolid or orthographic fisheye lenses exist. For more information see Fisheye Projection (PanoTools wiki). Visually, these projections differ by the amount of compression or stretching of the image near the edge of the fisheye circle. PTGui up to version 10 simply modeled every fisheye lens using the equidistant projection. The deviation of the actual projection from equidistant projection was compensated for by using the a/b/c lens distortion correction polynomial. This worked, but with caveats: because the relation between focal length and field of view differs for each kind of projection, PTGui could misestimate the size of the cropping circle for circular fisheye lenses. And secondly, the control point generator would have more difficulty finding control points (especially near the edges of the image) if the wrong fisheye projection was used.

In PTGui 11 this was solved by introducing the Fisheye Factor parameter. Fisheye lenses are now modeled using the following formula:



Here, k is the fisheye factor, f is the focal length, θ is the angle of the light ray entering the lens and R is the radial distance from the image center of the projected light ray.

By varying the fisheye factor k the equation morphs into the different fisheye projections. Values of the fisheye factor for the common projections are:

Equidistant: k = 0
Stereographic: k = 0.5
Orthographic: k = -1.0
Equisolid: k = -0.5
Rectilinear (non-fisheye): k = 1.0

In normal use of PTGui the fisheye factor is initialized to the known value of the lens before running Align Images. PTGui knows the fisheye factor for many common models of fisheye lenses. If EXIF data is available PTGui can often recognize the brand and model of the fisheye lens automatically, and set the fisheye factor accordingly. If no EXIF data is available, the brand and model of the fisheye lens can be selected from a list. In practise no lens follows the above projection model exactly, therefore a/b/c lens distortion correction is used to compensate for any remaining small differences between the ideal and actual projection.

The fisheye factor of a lens can be determined by the PTGui optimizer. When optimizing the fisheye factor, care must be taken to avoid interference by the a/b/c lens distortion correction parameters: in the Lens Settings tab, press the Reset button to reset a/b/c to zero. Then in the Optimizer tab, enable optization of the fisheye factor and disable optimization of a/b/c. As always, for accurate optimization of the lens parameters, images without parallax should be used.
3.29. Can I install different versions of PTGui side by side?
Yes, this is possible. Any version (trial, Pro, beta) can be installed in parallel to your current version of PTGui. In Windows, the installer will ask you for an installation folder (e.g. C:\Program Files\PTGui) and a Start Menu folder. If you enter different folder names, your current version will not be overwritten. On Mac, PTGui is distributed in a disk image (.dmg file). Double click the .dmg file to mount it. Inside there's the PTGui application. Drag the application to the desktop, then rename the application. Finally move the application from the Desktop into the Applications folder.

PTGui project files will by default be opened in the last installed version. To change this under Windows: right click on a PTGui project file, at 'Opens With' click on Change, click 'More Apps', click 'Look for another app on this PC', then browse (under Program Files) to the particular version of PTGui to use.

On macOS: ctrl+click on a PTGui project file, select 'Open With', 'Other...', select the PTGui application to use, enable 'Always Open With' and click Open.

Keep in mind that the settings and license information are shared by all PTGui applications for the current user.

If you accidentally overwrote your licensed version of PTGui with a trial version, you can re-download your licensed version even if it was an older version; see Q1.8.
3.30. I've upgraded from PTGui 11 to PTGui 12 and now my panoramas look different.
Many new features have been added to PTGui 12: automatic optimum seam placement, a new 'zero overlap' blending algorithm, color management and a new HDR processing workflow. Internally all processing is now done on linearized floating point pixel data. A new Post Processing side bar was added to the panorama editor for adjusting the toning curve and image saturation. The toning curve is now applied to raw files, which would look somewhat dull in PTGui 11. Color management ensures that out-of-gamut colors and clipped highlights after stitching and blending are properly handled.

Automatic seam placement in PTGui Pro 12 means that the seams will be placed entirely different from PTGui 11. Generally this will make stitching errors less noticeable, but as a side effect objects may suddenly appear in the PTGui 12 panorama which would be hidden in the PTGui 11 panorama. It's possible for example that PTGui 12 decides to show the tripod in the nadir of the panorama if this is considered to result in the optimum seam placement. This may happen even if a separate nadir image without tripod is available. PTGui is not smart enough to understand that the tripod is something you don't want to show in the panorama. The solution is to mask any unwanted objects using red masks in the Mask tab. Just a coarse mask or a couple of red dots is sufficient: PTGui understands the mask is part of something that should be removed and it will attempt to route the seams around the entire object.

Also, automatic seam placement will cause the outer part of the source images to be used more, whereas PTGui 11 would simply place the seams in the middle of the overlap area, as far away as possible from the edges of all source images. Some lenses at wider aperture have better image quality in the center, and PTGui 12 may decide to use some of the worse parts of the source image. Again, seam placement can be adjusted by adding green or red masks.

Automatic seam placement can be disabled entirely by disabling 'Find Optimum Seams' in the Blending side bar of the panorama editor. You'll also find a 'precision' slider there: moving this slider to the right will cause PTGui to calculate the seams at a higher resolution. But be careful, at the highest 1/1 setting it will take several minutes, or even hours, and use much memory. And the seams must be recalculated after every change to the panorama.

Another thing that's changed in PTGui 12 is the blending. The new Zero Overlap blending algorithm works very well in combination with optimum seam placement. Because it doesn't use any overlap it will give seamless results even if the seam is routed just very close around an object. The traditional multiband blending algorithm needs a certain amount of overlap and will cause the excluded object to still appear as a faint 'ghost' image if it is close to the seam. In general, Zero Overlap blending can also cope better with moving clouds and waves in water and it better handles exposure differences. But it may have trouble with finely patterned surfaces like ceilings or carpets. Also if a seam cuts through a moving object this may be more visible than with multiband blending. You can switch between Zero Overlap and Multiband in the Blending side bar to compare the results.

To get the same blending as with PTGui 11: disable 'Find Optimum Seams' and choose 'Blender: Multiband'.

Handling of raw files was improved by adding a toning curve, but if you prefer the less contrasty look of PTGui 11, go to the Post Process tab in the panorama editor and reduce the 'Shape' and 'Shift' sliders of the Toning Curve closer to zero. Fine adjustments to the slider can be made by holding down the Shift key while dragging the slider. Settings can be saved to a file or to a template. And keep in mind that PTGui does not intend to replace a dedicated raw converter: images will definitely look better when you convert your raw files in Photoshop, Lightroom or another raw converter (see Q3.7).

The new Toning Curve is also applied as part of tone mapping. The Post Processing tab replaces the Contrast and Saturation settings that were previously available in the Tone Mapping settings.

Handling of bracketed images has changed in PTGui Pro 12. In PTGui Pro 11 it was possible to stitch an HDR panorama from bracketed images without linking the images. In PTGui Pro 12, linking bracketed images is mandatory! Linking is required for getting optimum seam placement to work: when creating blend planes, the seams must be placed in the same location in each blend plane. To calculate the seams, PTGui must know which images belong to the same bracketed set, and you tell this by linking the bracketed images. If the images were taken by using the camera's auto bracketing, they will follow a repeating exposure pattern. PTGui will recognize this and offer to link the images when running Align Images. You can also force PTGui to link the images by selecting Images -> Link HDR Bracketed Exposures. If PTGui reports that no bracketed sets were detected, this means that the exposure pattern is not repeating in exactly the same way for each bracketed set. You can still link images manually: go to the Source Images tab, select a group of images, right click and choose 'Link Selected Images'. Repeat this for all bracketed sets.

Not linking bracketed exposures will lead to unexpected results in PTGui 12: the automatic optimum seam placement may decide to include or exclude entire images, because the same area is covered by multiple overlapping (bracketed!) images. Zero overlap blending will cause the excluded images not to be used at all. And optimizing or otherwise editing the panorama may completely change the seams, causing entirely different source images to be flipped into the panorama even when making just minor changes. Again, do Images -> Link HDR Bracketed Exposures to make sure that the images are linked.

Even though images have to be linked, it's still possible to use hand held bracketed images. When linking the images, just tell PTGui that the images were not taken from a tripod. The images will get independent yaw/pitch/roll coordinates even though they are linked. There's a new 'Link' checkbox in the Image Parameters tab to configure this for each set of bracketed image separately.
3.31. I've upgraded from PTGui 11 to PTGui 12 but stitching is much slower now!
PTGui Pro 12 performs automatic optimum seam placement. Calculating the best location of a seam among millions of pixels takes considerable processing time. It's also something that cannot easily be done in parallel: using a different starting point may result in a completely different optimum seam. Seam placement has a cascading effect: changing the seam at one side of the panorama may eventually affect the position of another seam at the opposite side. This cascading means that the seams have to be calculated sequentially and the process therefore cannot make efficient use of multiple CPU cores or the GPU.

If optimum seam placement is not desired, it can be disabled in the Blending side bar and the panorama will be stitched much faster. Switching to Multiband blending will speed up stitching even more, the new Zero Overlap blending is somewhat slower.
3.32. Does PTGui use cube faces internally as part of the stitching process?
No, when stitching source images into a spherical panorama, PTGui projects the images directly into the selected output projection (equirectangular generally). An intermediate cube face representation is not used.
3.33. What kind of tiles does the PTGui Viewer use internally?
The PTGui Viewer uses a custom 14 face polyhedron as the internal representation.
3.34. When was PTGui first released?
The first (beta) version of PTGui was released 10th of July 2000. Originally PTGui was a front end to Helmut Dersch's Panorama Tools library. Even though PTGui has improved much over the years, and it is not using Panorama Tools anymore, the workflow is still similar. Even the first beta version was already capable of stitching spherical panoramas.
4. Troubleshooting

4.1. I am trying to edit the seams of a layered panorama in Photoshop, but I only see the bottom layer with the merged panorama; the other layers are transparent.
This is by design. The idea is to use the blended panorama as the basis for retouching, selectively revealing parts of the source images for retouching by making the masks opaque.
4.2. Another application crashes when opening TIFF files generated by PTGui, or it displays garbled images.
TIFF is a container format which can contain many different types of image data; almost no application supports all possible TIFF formats. PTGui can create 16 or 32 bit TIFF files and TIFF files with an alpha channel but these features are not supported by many applications. If you need create a compatible TIFF file, press the 'Settings' button in the Create Panorama tab, and choose: 8 bits, no alpha channel and no compression. The resulting file can be opened in nearly every application that supports TIFF files. Also keep in mind that not all TIFF capable applications can read BigTIFF images, so they will fail to open TIFF files larger than 4GB.
4.3. My computer crashed while PTGui is running
A normal application like PTGui (i.e. not a driver or a kernel process) is unable to crash an entire computer; the worst that could normally happen is the application itself crashing but not the entire computer. The operating system will be able terminate any misbehaving application. If the computer crashes, shows a 'blue screen' error or spontaneously reboots this is usually indicating a problem with the hardware or a driver.

The GPU is the most likely culprit: probably the problem will resolve by disabling GPU acceleration in Options - Advanced (Windows) or Preferences - Advanced (Mac). If you have an nvidia GPU, nvidia's 'Game Ready Driver' is known to cause issues, in particular when running multiple GPU accelerated applications at the same time. To resolve this, install their stable 'Studio Driver' instead. Download nvidia drivers here. For AMD graphics cards: download AMD drivers here.

The GPU cannot be shared well with other applications; if you use (for example) Adobe Lightroom at the same time, disable GPU acceleration in either Lightroom or PTGui.

If the computer does not crash but rather becomes unresponsive while running PTGui, this might be caused by PTGui using more RAM than is available. This may happen if other memory hungry applications are run at the same time. You can reduce the maximum amount of RAM used by PTGui in Options - Advanced (Windows) or Preferences - Advanced (Mac). For a start try setting this to half of the amount of physical RAM.

If you observe crashes in PTGui but the operating system continues to run properly then this could be a bug in PTGui. The Windows version of PTGui includes a crash reporter; we encourage you to submit the crash data to us for analysis. Mac users please send the crash report to us at support at ptgui dotcom; crash reports on the Mac can be found in <User>/Library/Logs/CrashReporter/.

If you keep encountering problems, please post to the PTGui support forum, we'll be happy to help you.
4.4. PTGui shows a message 'PTGui was unable to detect control points for some of the images, therefore you need to add a few control points by hand'. Help! What should I do now?
When you press Align Images, PTGui analyzes your source images and looks for details which can be seen in multiple images. For example, the corner of a building might be visible in the right hand side of one image and in the left hand side of another image. On these matching details PTGui places so called Control Points. To see what control points look like, go to the Control Points tab in PTGui after you have run Align Images. In the Control Poins tab select two overlapping images by clicking the thumbnails above the images and you will see numbered markers indicating the matching features. Ultimately the control points are used by PTGui to set up the panorama: it warps and moves the images in such a way that the control points match as closely as possible.

If you see the above message, this means that PTGui was not able to find control points for all images. The human eye is still better in recognizing patterns than a computer and in this case you will need to help PTGui a bit. To do so, first open the Control Point Assistant (in the Tools menu). The Control Point Assistant will tell you what the problem is, for example 'Image 4 does not have any control points'.

Besides single images lacking control points it's also possible that there are clusters of images linked by control points: for example image 1,2 and 3 are linked by control points and image 4,5 and 6 are linked by control points, but there are no control points between images in either cluster. To create a panorama all images should directly or indirectly be linked by control points, so in this example adding control points between image 3 and 4 would solve the problem.

Suppose the Control Point assistant tells you that image 4 does not have control points: go to the Control Points tab in the main window, and choose image 4 in the left pane. In the right pane find an image which partially overlaps image 4 (most likely image 3 or image 5). Find an object which is visible in both images, click on that object in the left image and click on the same object in the right hand image. As you see a colored marker has been added. Repeat this until you have added at least 3 control points. Then go back to the Control Point Assistant and see if there are any other images that need control points.

When done, go back to the Project Assistant tab in the main window: the above error message is now gone. As the last step the project needs to be optimized: click on the blue underlined link to do this. The optimizer will re-align the images such that the control points match as closely as possible. Verify the result in the Panorama Editor window: the panorama should now be set up properly.

The above workflow is shown in detail in our Video Tutorial.

Sometimes an image contains no recognizable details at all (for example if the images contains pure blue sky only). In that case see Q6.28.

For more information use the on line help available for the Control Points tab and the Control Point Assistant window: in most screens you can get context help by pressing F1 (Windows) or Fn+F1 (Mac).
4.5. PTGui is randomly rotating my images!
The orientation of the images the main window is synchronized with the orientation of the images in the stitched panorama. For example, if you rotate an image in the Panorama Editor 90 degrees clockwise, the image thumbnail in the Project Assistant will be rotated clockwise as well. And if you rotate the entire panorama 90 degrees, all images in the Project Assistant will be rotated too.

If PTGui seems to randomly rotate your images after running Align Images, most likely it was unable to properly align the panorama, resulting in misaligned and randomly rotated images in the Panorama Editor. It may seem that the misalignments are caused by the random rotation but it is in fact the other way round: due to the misalignments the images get randomly rotated in the panorama, and the orientation of the images in the Project Assistant simply reflect the orientation of the images in the panorama.

Also see Q6.44.
4.6. I'm having trouble stitching my panorama. Can you help?
First of all, if you are new to PTGui check out our Video Tutorial. It may help you understand what the problem might be. In particular make sure that all images are taken from exactly the same viewpoint and that the camera is rotated around the entrance pupil of the lens (which is usually close to the front of the lens). In general a regular tripod is not suitable for taking panoramas; you need a dedicated panoramic head to ensure that the camera is rotated around the front of the lens and not around the tripod screw.

If this does not solve the issue please post your panorama to the PTGui support forum and we'll be happy to take a look. Large files cannot be uploaded to the forum directly; instead create a zip file with your panorama and upload it to a file publishing site such as wetransfer, Dropbox or Google Drive. Then include the URL of the uploaded file in your forum post. To allow us to help you quickly, upload at least the PTGui project file (.pts). Depending on the problem we may need the image files as well.
4.7. After editing a 360 degree panorama in Photoshop and importing back into PTGui, I'm seeing a vertical line in the panorama
This is caused by the fact that Photoshop isn't aware that the left and right edge of the image wrap around. When doing local adjustments (in particular contrast enhancement) near one of the edges, pixels at the other edge should also be taken into account, otherwise a hard edge will be visible when the panorama is later wrapped around in a panorama viewer.

You can work around this limitation in Photoshop by extending the panorama: a section from the right hand side of the panorama is pasted next to the left hand side, and vice versa. Subsequent adjustments will then take properly into account the pixels 'over the edge'. When done editing, reduce the panorama to the original size.

We've created a set of Photoshop scripts to accomplish this with a single mouse click: download PhotoshopExtendCanvas.zip. Please see readme.txt inside the zip file for installation instructions.
4.8. When installing on a Mac I get the error "PTGui Pro cannot be opened because the identity of the developer cannot be confirmed. macOS cannot verify that this app is free from malware."
This may happen when installing older versions of PTGui on newer versions of macOS. Apple has locked down macOS to only allow running signed applications. Over the years Apple has changed the requirements for signing multiple times. The current PTGui version has the proper signatures but older PTGui versions will be rejected by macOS.

The signature verification can be bypassed as follows: Ctrl+click on the PTGui application, select 'Open'. In the subsequent warning window, click 'Open'.
4.9. I'm unable to open a QuickTime VR .mov panorama
QuickTime VR (or QTVR) was a special dialect in the QuickTime .mov video format supporting interactive playback of spherical panoramas. For many years this has been the format of choice for embedding panoramas in web pages: the QuickTime plugin was installed on every Mac and on many Windows computers (it was included with iTunes for Windows). With the introduction of QuickTime X in 2009, Apple has dropped support for QTVR panoramas. These days HTML5 is the format of choice for displaying panoramas on web pages (see Q6.15).

QTVR panoramas can still be viewed by installing QuickTime 7, but be aware that this creates a security risk: exploits for QuickTime 7 exist and Apple is no longer updating the software. That said:
Installing QuickTime Player 7 on your Mac
Download QuickTime 7 for Windows.
Windows users can alternatively use the DevalVR player (Unicode) which can also play back QTVR panoramas.

Pano2VR can be used to convert an existing QTVR .mov file to another format.
4.10. I'm attempting to stitch images taken with multiple cameras but I'm running into stitching errors
Seamless panoramic stitching requires that all images are taken from exactly the same viewpoint. Moving the viewpoint causes parallax which makes it impossible to stitch images perfectly. For more information about parallax see Q5.4 and watch the Video Tutorial.

This requirement is very critical: even photos taken from viewpoints spaced only a few centimeters can have significant parallax, causing clearly visible stitching errors on nearby objects. When taking panoramas with a single camera parallax should be avoided by using a panoramic tripod head: this ensures that the camera is rotated around the 'no parallax point' which is usually located near the front of the lens.

When using multiple cameras, parallax is unavoidable which means that it is simply impossible to stitch the images perfectly. This problem is particularly apparent in panoramic video because this can only be created from multiple cameras. The only real 'solution' is to lower your expectations and accept that stitching errors will be visible. That said, for the best results consider the following:
4.11. My panoramas stitched using a template in the Batch Builder have misalignments. This only happens in the Batch Builder; the panorama is perfect if I use the same template in the GUI.
Essentally there are two different use cases for the batch builder:
  1. To stitch many panoramas using the exact same settings, without generating control points. This can be used for example with multi camera rigs, where all panoramas are guaranteed to have the same image orientations.
  2. or to automatically stitch a number of panoramas by just pointing PTGui to a folder with images. The images are taken for example by rotating the camera on a panoramic tripod head.
In the latter case the image positions in each panoramas will usually be slightly different. Even if the panoramic head has click stops, mechanical tolerances will cause small variations in the image orientations in each panorama. To compensate for this PTGui should analyze the images for each panorama and generate control points.

Whether the batch stitcher will generate control points is controlled by this setting in the project:
Project Settings -> Batch Stitcher actions -> Do 'Align Images' and save the modified project
This option should be checked in the template used in the Batch Builder, unless the image positions in each panorama will be absolutely identical.
4.12. The Batch Builder seems to ignore the settings in my template; my panoramas come out different than expected.
If you are using a multi camera rig and need all panoramas to be stitched absolutely identically, uncheck this setting in your template:
Project Settings -> Batch Stitcher actions -> Do 'Align Images' and save the modified project
Also see Q4.11.

If you do require PTGui to generate control points but would like to keep the panorama size and projection as set in the template, see: Q6.24.
4.13. The panorama in the PTGui Viewer is full of black dots!
This is a known issue caused by a bug in Intel's graphics driver. It's affecting the PTGui Viewer only, the stitched panorama from PTGui should be fine. The problem seems to be limited to Windows computers with dual graphics processors (both a low power Intel integrated GPU and a more powerful AMD or NVIDIA discrete GPU). The problem can be solved by updating the Intel graphics driver. For laptops a driver package is usually made available on the laptop manufacturer's website. Look for the driver package including the Intel graphics driver.

If a driver update is not possible, the problem can be solved by telling Windows 10 to always use the AMD or NVIDIA graphics (and not Intel's integrated graphics) for the PTGui Viewer: Another alternative is to use FSPViewer (which doesn't use OpenGL) instead of the PTGui Viewer. See Q6.29.
4.14. I'm using PTGui 10; the stitching process hangs and never completes.
This may happen on Windows machines with NVIDIA graphics hardware. Recently NVIDIA have released a driver update for Windows which appears to break GPU acceleration in PTGui 10. The problem does not seem to affect PTGui 11 and later.

If you don't wish to upgrade to PTGui 11, you may do one of the following:
4.15. Panoramas published using Publish to Website are not displayed correctly using Firefox, the image is flashing.
This problem occurs with older versions of the PTGui web viewer on recent versions of Firefox. It is fixed in the current version of the PTGui Viewer. Web pages created with Publish to Website in PTGui 11.28 should not exhibit the problem.

For panoramas created with earlier versions the problem can be fixed by updating PTGuiViewer.js on your web server. Download the latest PTGui Viewer here and replace PTGuiViewer.js on the web server with the latest version. Right-clicking in the panorama on the website should show 'PTGui Viewer version 2.6' (or newer). If you still see the old version, clear the browser cache or append a random query string to the url in the html page like this:
<script src="PTGuiViewer.js?random=2878342342">
This will force the web browser to use the new version.
4.16. The brightness or contrast in the Detail Viewer differs from the stitched panorama!
This is a known limitation of the Detail Viewer when using Tone Mapping or Exposure Fusion. Tone Mapping and Exposure Fusion make local contrast adjustments to the image. Adjustments in a particular area are influenced by the image contents surrounding that area. For example, if the sun is visible in the panorama, Tone Mapping and Exposure Fusion will darken the areas in the sun's neighborhood.

This means that to properly apply Tone Mapping or Exposure Fusion, the panorama must be processed as a whole. But the the Detail Viewer only sees a part of the panorama. Suppose the sun is just outside the visible area of the detail viewer, and then the Detail Viewer's orientation is moved until the sun becomes visible. This will completely change the tone mapped image.

In other words, Tone Mapping and Exposure Fusion in the Detail Viewer offer just an approximation. The actual result can be seen in the Panorama Editor. A quick preview can be generated by pressing the 'eye' toolbar button in the Panorama Editor, or through the Preview Tab in the main window.
4.17. I'm getting an error message "These images cannot be linked because they have different dimensions. Linked images should have the same pixel dimensions." Why?
You may see this message when linking bracketed exposures for HDR. Usually the images will have the same number of pixels but the problem is caused by different image orientations (portrait vs. landscape) within the bracketed set. In general PTGui can deal with mixed image orientations, except when working with bracketed images. Linked images must have the same dimensions and orientation.

Image orientation can be encoded in the image in two different ways: the image may be physically rotated in a specific orientation, but it's also possible that the rotation of the images is encoded using the EXIF 'Orientation' tag. In the latter case, portrait and landscape images may actually be stored in the same physical orientation (usually landscape), and they will only differ in their Orientation tag. In this case the problem can be worked around by telling PTGui to ignore the orientation tag:
If the images are physically rotated differently (in other words it's not just a different Orientation tag), the above solution will not work and the problem can only be solved by rotating the images in an external image editing program before loading in PTGui.

Again, note that this limitation only applies to images within a bracketed set. Usually the problem happens when shooting bracketed nadir images: when the camera is pointing down, the orientation of the image (portrait or landscape) is ambigious. But we think a camera should use the same orientation for each group of bracketed images, it shouldn't randomly rotate images in a bracketed set. Tell your camera manufacturer that PTGui thinks this is a bug.

For many cameras the automatic orientation sensor can be switched off; this is recommended when shooting panoramas.
4.18. One of the source images is not included in the blended panorama. Why is that?
Since version 12, PTGui Pro performs automatic optimum seam placement. If an image is entirely overlapped by other images, the seams may be placed such that the image does not get used at all in the blended panorama. The panorama is fully covered by all other images.

The seam finder attempts to route seams around objects, so the object will either be included or removed completely. But PTGui can't know if the object is something you want to keep or exclude. So for example it's possible that the tripod remains visible in the nadir even if you added an additional nadir image, with the tripod removed, to cover it.

You can tell PTGui Pro to use a particular image by adding a green mask in the Mask tab. Often a small dot of green mask is sufficient; the optimum seam finder will enlarge the area such that the seams will be the least noticeable.

It's also possible to disable optimum seam finding altogether in the Blending side bar of the panorama editor.
4.19. The image in the Detail Viewer looks different from the final panorama. I'm using exposure fusion / tone mapping.
The Detail Viewer only shows a small section of the panorama. But generating an accurate preview of the tone mapping or exposure fusion can only be done by rendering the entire panorama. So the preview in the Detail Viewer is inaccurate when using exposure fusion / tone mapping. To get an accurate preview, go to the Preview tab in the main window, create a preview of the entire panorama and view it in the PTGui Viewer.

Tone mapping and exposure fusion perform local contrast adjustments to the image. The adjustments to part of the image will influenced by the surrounding image content. For example, if the Sun is visible in the panorama, it's brightness will influence the tone mapped (or exposure fused) image around it. If the Detail Viewer shows a part of the panorama not containing the sun, the sun's bright pixels will not be taken into account, so the preview will not be an accurate representation of the full tone mapped panorama.
4.20. PTGui is dislaying OpenCL errors, or the computer crashes while running PTGui on a Windows computer with NVIDIA graphics.
For GPU acceleration to work reliably on NVIDIA GPUs it's important to run their latest so called 'Studio Driver'. NVIDIA also offer a 'Game Ready' driver but this is known to cause crashing or even blue screen reboots on Windows. See NVIDIA Driver Downloads.

Running other GPU accelerated applications (Lightroom, Capture One, etc) while stitching panoramas will also cause problems.

If all fails, there's always the option of disabling GPU acceleration in Options - Advanced. PTGui will run fine without GPU acceleration, just slower.
4.21. In Finder on my mac, all raw files are listed as type 'PTGui RAW'
This happens if macOS has decided to make PTGui the default application for handling files of this type. In other words, double clicking on a raw file will open the file in PTGui. Changing the default application will also change the displayed file type.

You can change the default application in macOS as follows:
Or see this guide with screenshots: How to set default apps on Mac.
4.22. I'm trying to level the panorama by dragging in the panorama editor. The panorama only moves; the curvature doesn't change.
Normally a panorama can be leveled by dragging in the panorama editor; see the Video Tutorials, Part 4. For wide angle panoramas, dragging up or down will change the curvature of the horizon. This is due to the way the wide angle image is projected onto the flat surface of the equirectangular image (as explained in the video). For narrow angle panoramas, the curvature is insignificant: dragging the panorama will only shift the image instead of changing its shape.

If you have a wide angle panorama, but dragging only shifts the image instead of curving, this would mean that the panorama in PTGui has a narrower field of view than in reality. This is the result of PTGui using a longer lens focal length than the actual lens. A longer focal length results in a narrower field of view.

To fix the problem, go to the Lens Settings tab (you may need to switch PTGui to Advanced mode) and check the focal length displayed there. If the value deviates significantly from the actual focal length, fix it by entering the proper value. To prevent the optimizer from undoing your change, go to the Optimizer tab and uncheck the box 'Optimize lens focal length'. Then run the optimizer by pressing the Run Optimizer button. The result will be a much wider angle panorama and the Panorama Editor will now show only a small fraction of the panorama. Drag the horizontal and vertical sliders to increase the field of view, or press the 'Fit Panorama' button in the Panorama Editor. Also make sure the panorama is using equirectangular projection (PTGui might have chosen rectilinear initially because of the narrow field of view). Now, dragging the panorama up or down should work as expected.

Usually the problem is caused by parallax. Normally PTGui will be able to estimate the focal length correctly. But in the presence of parallax there will be unrecoverable misalignments in the panorama. The optimizer will do its best to adjust the panorama until the control points match as good as possible. The best optimization result might happen if a significantly different focal length is used. In other words, the focal length is adjusted in an attempt to minimize the parallax errors.

Especially when shooting panoramas hand held, it's crucial to avoid parallax. The front of the lens should stay in the same position while taking the images. The camera should be rotated around the front of the lens. Don't rotate the camera around your body when taking the photos.
4.23. PTGui reports 'failed to initialize OpenCL'
See: Error: failed to initialize OpenCL.
5. Improving the results

5.1. The horizon of my panorama is curved instead of straight
See the Video Tutorials, Part 8: Levelling.
5.2. I get color/brightness differences between the images in my panorama
First of all always make sure to lock the exposure and white balance of your camera. Color differences can be corrected to a certain amount by the blending process, but you will get the best results by locking the color balance and exposure when shooting the images.

Exposure is locked by choosing the M mode if your camera. To lock white balance, choose one of the white balance presets on your camera that match the current lighting, such as 'Cloudy' or 'Sunny'.

Even with color balance and exposure locked you may still see get small differences in brightness due to vignetting. PTGui can correct for this, see Vignetting correction with PTGui.
5.3. How can I change the resolution (ppi or dpi value) of the generated panorama?
This can be changed in the Metadata tab. Switch to Advanced mode to reveal this tab.

Be aware though that the resolution of an image has nothing to do with image quality or print quality. The ppi/dpi value of an image file is just a number embedded in the header of the file, suggesting the number of pixels to be printed in one inch. You could set the resolution to a very large dpi value but this will not modify the image in any way, except that the image would be printed smaller (and thus have more pixels per inch).

The number of pixels is what really matters: if you need a more detailed output image, increase the width and height of the output image instead (on the Create Panorama tab). Click the '100%' button in the Create Panorama tab to achieve the highest quality. Increasing the output size beyond the optimum size is possible but will only increase the file size, not the amount of visible detail, since the latter is limited by the (angular) resolution of the source images.

Also see: The Myth of DPI.
5.4. I see misalignments in the stitched panorama. What can I do to improve the result?
Parallax: First of all, make sure that the photographs are taken properly: for panoramas, all images should be taken from exactly the same viewpoint. More in particular: the camera should be rotated around the 'no parallax point' (sometimes referred to as the 'nodal point') of the lens. For most lenses this point is located near the front element; since it does not coincide with the tripod screw of the camera, you will need to use a so called panoramic head. If the camera is not rotated exactly around this point, parallax errors will occur, preventing a perfect stitch. Don't attempt to take a panorama from a tripod without using a panoramic head, you'll get serious stitching errors.

In about 4 out of 5 support questions we receive regarding stitching problems, parallax turns out to be the reason for the problem. For an introduction to parallax please see for example: Finding the no-parallax point by John Houghton. Be sure to also watch our Video Tutorial: parallax is explained in the first video.

Florian Knorn made an in depth video tutorial on calibrating a panoramic head.

The impact of parallax errors differs per scene: for a landscape panorama, with no objects close to the camera, a limited amount of parallax might not be a problem and such a panorama can easily be taken handheld. But for panoramas of room interiors even a small misplacement of the camera of just one centimeter or inch will result in clearly visible stitching faults. Creating a good interior panorama is therefore impossible without using a tripod and properly calibrated panoramic head.

In contrast to (e.g.) barrel distortion, correcting for parallax faults in software is impossible. This is not a limitation of PTGui but a physical limitation. If you must stitch images with parallax, the best you can do is to mask the faults after stitching by placing the seams appropriately (see our post processing tutorial) but this can be a lot of work and often does not lead to perfect results. Parallax problems lead to overall high control point distances: if you have many control points with an optimized distance of 20 or more (see below), this usually indicates a parallax problem.

Misplaced control points can be another reason for misalignment. Especially if there are repeating structures in the images, the control point generator may occasionally misplace one or two control points. The same can happen if there are moving objects in the panorama: slowly moving clouds in the sky are notorious in particular (also see Q6.42). Finding these misplaced control points is easy: open the Control Point table (Ctrl+B on Windows or Cmd+B on Mac) and find the control points with the largest distance. This distance indicates the alignment error of the control point in the panorama. By default, the table is sorted in descending distance, so the worst aligned control points are in the top of the list. In general, a distance below 5 is sufficient, while higher values usually indicate a problem. Double click on a control point in the table to edit it, or delete it by pressing Del.

Misalignment in an area of a panorama can occur if there are no control points in that particular area. Go to the Control Points tab and add a few points in problem areas to improve the alignment there.

A common misconception is that using a wide angle lens would cause misalignments, due to the distortion inherent to wide lenses. This is not true: PTGui can perfectly correct perspective distortion and barrel distortion in wide angle lenses. A panorama from a wide angle lens will thus look exactly the same as the same scene taken with a long lens, apart from any differences in quality and resolution.
5.5. Some control points in my project have a relatively high control point distance. Will the alignment of my panorama improve if I delete all control points with an error above a certain threshold?
No, not necessarily. When editing control points you should not just aim for the lowest possible control point error. Instead the goal should be to keep all control points that are placed correctly, and delete only the faulty ones. Faulty control points include for example points placed on moving objects such as people, clouds and cars, and control points placed incorrectly on different objects. The latter may happen in particular with repeating structures.

Often these misplaced control points have a higher than average control point error, but the reverse is not true: not every control point with high error is a faulty one. If you have a control point pair with a large error but with both markers placed on the same spot on a non-moving part of the panorama, then this control point actually improves the alignment of that particular area in the panorama. Therefore it should be kept rather than deleted, even though this increases the average control point distance.

If you are consistenly getting control points with high errors (say, 5 or higher) then this most likely means that your images suffer from parallax. Only images without parallax can be stitched perfectly. See Q5.4 for more about parallax.
5.6. My drone panoramas are showing misalignments at the horizon. How can I get a straight horizon?
Ultimately these errors are caused by parallax: if the camera has been moved between taking the first and last images, foreground objects will have shifted relatively to background objects. If control points are placed on nearby objects, PTGui will attempt to align those objects but stitching errors will result on objects far away (i.e. anything on the horizon).

In drone panoramas usually the misalignment will be most severe between the first image and the last image in the sequence, due to the drone drifting over time. Especially altitude drifting will lead to clearly visible stitching errors at the horizon, because a vertical misalignment at the horizon is extremely noticable.

One workaround for parallax is to remove all control points on nearby objects and only keep control points on objects further away from the camera. This effectively removes the parallax and results in a perfectly straight horizon. But this will come at the expense of stitching errors on foreground objects. Those stitching errors would need to be retouched manually.

Often a better alternative is to use Viewpoint Correction on all images except one. Viewpoint Correction is available in the Pro version of PTGui. Although Viewpoint Correction is intended to be used on flat surfaces only, it can work quite well on drone images even when the surface is not actually flat.

Proceed as follows:
Usually this will result in a well aligned panorama with a straight horizon. Keep in mind though that Viewpoint Correction may result in slanted (i.e. non-upright) buildings. This is not very noticable if the parallax was caused by altitude differences, but if the drone moved sideways you may see nearby high rise buildings leaning slightly to one side.

Also, when optimizing Viewpoint, it's important to keep at least one image without Viewpoint Correction. The corrections in other images will be 'anchored' to this image. If viewpoint optimization would be enabled for all images, the optimizer is given too much freedom and may distort all images extremely in order to minimize the misalignments. Therefore one of the cells in the 'Viewpoint' column in the Optimizer tab should be set to 'Reset'.
6. How to...

6.1. My panorama contains curved lines. How do I get straight lines to remain straight in the panorama?
You would need to use the rectilinear panorama projection. Rectilinear projection is the only projection that preserves all straight lines; all other projections will curve certain lines. Unfortunately rectilinear projection is limited in practise to a maximum field of view of about 120 degrees, so there is no way to preserve straight lines for wide panoramic scenes in a single image. This is not a limitation in PTGui but a physical limitation.

For more information see: Projections

But by using an interactive panorama viewer it's possible to show a wide panorama while preserving straight lines: the panorama viewer only renders a narrow rectilinear view in a certain viewing direction. The user can look around in the entire scene by changing the viewing direction. See Q6.15 and Q6.29.
6.2. How do I use the Horizontal line and Vertical line control points?
See part #8 of our Video Tutorial series.
Also, John Houghton wrote an excellent tutorial.
German readers see this page by Bernhard Vogl
6.3. How can I calibrate my lens parameters?
For panoramic stitching you don't need to know the lens parameters since PTGui calibrates your lens automatically for each panorama. But knowing the lens parameters can be useful if you (for example) would like to correct a single image for barrel distortion. The lens parameters can be calibrated accurately as follows:
  1. Take enough images to build a 360 degree, single row panorama. Make sure the images overlap by at least 30%. Make sure that the camera is rotated around the 'no parallax point' of the lens, in order to avoid parallax errors.
  2. Load the images into PTGui, and execute step 2 (Align Images) of the Project Assistant.
  3. Switch to the Control Points tab and review all generated control points. Remove any misplaced control points, and any control points on moving objects (including clouds in the sky!). Also remove any control points on nearby objects, since these will suffer the most from any remaining parallax errors in your setup. Make sure that each pair of overlapping images has at least 4 control points (more is better). Ensure that there are some control points in the corners of the images as well, not just in the center.
  4. Optimize the project using the Optimize button in the Project Assistant.
  5. Open the Control Point table (Ctrl+B or Cmd+B). The control point distances should be small, generally less than 3. If you find control points with higher distances, correct or remove them by repeating the previous two steps.
  6. Switch to Advanced mode by pressing the Advanced button in the side bar.
Now the optimized lens parameters can be found as the a, b and c parameters on the Lens Settings tab. Use the Lens Database button to save the values for later use.

Please note that different orientations (landscape vs. portrait) and different focal lengths (in case of zoom lenses) will result in different correction values, so be sure to save separate entries in the lens database for each zoom setting and for landscape and portrait orientation. Even at the same zoom setting and orientation subsequent calibrations may result in significantly different a/b/c values. This is normal, since completely different a/b/c values may represent very similar lens correction curves.
6.4. Does PTgui allow stitching of photos that have the camera in different locations?
In general this is not possible. PTGui was designed for stitching true panoramas, by taking overlapping photos from a single camera viewpoint. If the camera is moved between shots, parallax errors will occur. Correcting for parallax errors in software is physically impossible so in general it is impossible to stitch such images without visible misalignments.

There is one exception: if the subject to be photographed is flat, like a wall or like aerial photographs (shot from some altitude and without high rise buildings), parallax faults will not be noticable. Such images can be stitched in PTGui if the following conditions are met: Under these circumstances the photos can be stitched using the process for stitching mosaics, see the section directly below.

If the subject to be photographed is not too wide and the camera can be placed at sufficient distance, consider taking your photographs as a true panorama instead, from a single camera viewpoint. Choose a rectilinear panorama projection so that straight lines in the scene will remain straight in the panorama. The result will probably look better than when attempting to stitch images where the camera was moved between shots.
6.5. How can I stitch mosaics, like partial scans from a flatbad scanner of a large image?
PTGui was designed for stitching panoramas from photographs taken from a single camera viewpoint. When stitching a panorama, images are warped to correct for perspective distortion so that a seamless overlap is achieved. For mosaic-style stitching on the other hand the images should only be shifted and rotated; any perspective warping is undesirable. PTGui can be tricked to do no warping by setting the focal length to a very large value. When stitching images taken with a very long lens from a large distance, no perspective warping is needed, only transformation and rotation. This is similar to stitching mosaics.

So to stitch mosaics, proceed as follows: Your mosaic is now ready to be stitched at the Create Panorama tab.

Keep in mind that the above will only work if the image surface is absolutely flat. The camera should be pointing exactly perpendicular to the image surface and all images should be taken from exactly the same distance.

If the camera angle or distance was not constant, enabling Viewpoint Correction may help. To enable viewpoint optimization, first switch the Optimizer tab to Advanced. Then in the Viewpoint column select 'Optimize' for all images except one. It's important to keep one image without viewpoint optimization (select 'Reset' for that image). This will serve as an anchor against which the viewpoints of the other images will be optimized. Viewpoint optimization is available in the Pro version of PTGui only.

Using viewpoint correction for mosaics is not without drawbacks unfortunately: for mosaics consisting of many images, enabling Viewpoint Correction may cause the entire panorama to become slightly curved. Small alignment errors between each pair of images will add up, causing gradual changes in the panorama's shape. This problem can get severe especially if the image surface is not perfectly flat. Unfortunately the only way to avoid this is by not using Viewpoint Correction.

Stitching perfect mosaics is difficult; if possible, we recommend to shoot the image as a classical panorama, by shooting from a long distance using a long lens. Mount the camera on a panoramic tripod head to avoid parallax.
6.6. My panorama was taken with the camera tilted up or down. Now there's a lot of unnecessary black space above/below the panorama, increasing the size of the output. Can it be cropped away before stitching?
Yes, this is possible. Although the field of view sliders in the panorama editor always crop the panorama in a symmetrical way (keeping the horizon of the panorama in the middle), an alternative way to crop the panorama is by using the yellow crop lines which can be dragged from the corner of the image in the panorama editor. An example of this is shown on page 4 of the Quick Tour. The crop lines can be placed anywhere so this method is not restricted to symmetrical cropping.
6.7. How can I have better control of the overlap area (i.e. the location of the seams)?
The easiest way to achieve this is by using the Masking features in PTGui Pro. See the Video tutorial (part 6).

It's also possible to retouch a panorama in Photoshop after stitching, by using a layered output format; see the (old) Post processing tutorial.
6.8. How can I create a vertical panorama? PTGui rotates my panorama 90 degrees!
For single row panoramas, PTGui will always attempt to align the images in a horizontal row. This behavior cannot be changed, but you can easily rotate the panorama: in the Panorama Editor, simply use the right mouse button and drag the panorama to the right orientation. After rotating, you may need to press 'Fit Panorama' in the Panorama Editor to resize the panorama area so that it fits.

Vertical panoramas usually look best in one of the Transverse projections. You can choose a suitable projection in the Projection submenu of the Panorama Editor menu.
6.9. I want to cover the tripod in my (360x180 degree) spherical panorama. How do I add a nadir cap?
There are several options. Peter Nyfeler has created a Photoshop action for adding a mirror ball nadir cap.

Or you could use your own logo. The logo needs to be warped into the projection of the panorama, as follows: The result is a warped version of your logo. Overlaying the logo has to be done manually in a graphics editing program. A quick way to do this in Photoshop is by selecting the entire logo image (Ctrl-A), copying it (Ctrl-C) and then pasting it into the panoramic image (Ctrl-V). This creates a new layer in the panorama with the logo.

If you have PTGui Pro, instead of covering the missing parts consider using Viewpoint Correction to create a full panorama of the entire scene including the nadir. See the Viewpoint correction tutorial.
6.10. How can I change the default settings for new panoramas?
Choose 'Make Default' in the file menu to save the current settings as a starting point for new projects. This will save all settings, except for the images and control points. It works exacly like Apply Template but it is applied to every new project.

Even if you changed the defaults, the Project Assistant will still override certain settings in order to ensure a good result: it will adjust the field of view of the panorama to fit the contents and it will choose a suitable projection depending on the field of view. All of this can be overridden as follows (Pro version only):

6.11. How can I stitch extremely large panoramas?
If you have enough free disk space and a fast computer, PTGui can easily stitch hundreds or even thousands of images into a panorama. Not all file formats can be used though:
6.12. How can I align a set of images, all taken in the same direction (not a panorama)?
This can be done using PTGui; it can be used for (e.g.) accurately aligning a set of images for manual HDR creation, for making a time lapse movie, or for extending depth of field by merging images taken at different focusing distance.

It requires a special workflow though. By default, PTGui expects that a project contains overlapping source images, taken from the same viewpoint, but in different directions. The perspective changes that occur when the camera is rotated allow PTGui to accurately calculate the focal length (or field of view) of the lens. When all images are taken in the same direction, this information is missing and PTGui may end up optimizing the lens parameters to wrong values. This can result in a very small field of view, or introduce barrel distortion.

If the images are taken in one direction, they can be aligned in the following way:
  1. Load the source images in PTGui.
  2. Switch to Advanced mode by pressing the Advanced button in the side bar.
  3. If the goal is to combine bracketed images into a single HDR or tone mapped image, the images should be linked. To do so, go to the source images tab in PTGui Pro. Select all images, right click and choose 'Link Selected Images'. This ensures that the images will be merged to HDR instead of being blended as a regular panorama. Next, go to the Image Parameter tab and uncheck the 'Link' checkbox for all images. This ensures that PTGui is creating control points between the bracketed images in order to align them.
  4. Go to the Optimizer tab, uncheck 'Optimize lens focal length' and choose 'Minimize lens distortion: No'.
  5. In the menu bar, choose Control Points|Generate Control Points.
  6. Press F5 to launch the optimizer. The images are now aligned properly.
  7. In the Panorama Editor window, press the Fit Panorama button. Optionally adjust the field of view using the two sliders if you need to adjust the cropping of the output.
6.13. How can I use exactly the same stitching settings for different sets of images?
This can be achieved using templates (see Q3.9). Create the first panorama in the regular way and save the project file. For the subsequent panoramas do the following:
6.14. How can I correct a single image for lens distortion?
To do this, you first need to get the calibrated parameters of your lens, as described in Q6.3. Save the calibrated values to the lens database in PTGui.

To correct a single image: After the above steps, the project can be saved as a template. For subsequent images, start a new project, load the image to be corrected, choose File | Apply Template, and pick the template project.
6.15. How can I show a panorama on my website?
PTGui comes with a web panorama viewer and authoring tool. With a few clicks you can create the files needed to show your panorama on a website.

First stitch your panorama to a flat image in JPEG or TIFF format. It's best to use Equirectangular projection (click the Equirectangular button in the Panorama Editor). Make a note of the horizontal field of view of the panorama, this is shown in the status bar of the panorama editor window. Don't use the yellow cropping lines in the Panorama Editor: you'll need an image where the horizon is in the middle, otherwise the panorama viewer will distort the panorama into a curved shape.

Then go to Tools -> Publish to Website to open the authoring tool. For more information about the different settings consult the accompanying Help page. Press the Convert button to process the panorama. This creates a HTML page and 17 other files; all files should be uploaded to a folder on your web server. Then you may add a link from an existing page to the generated .htm page which will open the panorama.

Note that in order to upload the files, your web hosting company should give you raw access to the files being served. If they only offer you access to a Content Management System this may not be the case. In general this is referred to as FTP Access, so check with your web hoster whether they support this and consult their support for the FTP upload settings.

The PTGui panorama viewer automatically choses between 3 different technologies (Flash, CSS3D and WebGL) to display the panorama. This ensures that your panorama is viewable on almost every modern device, including smartphones and tablets.

It is however intended to be just a simple and quick way to show your spherical panoramas on a website. If you need more advanced features such as hotspots, custom buttons, etc, or if you need to display gigapixel panoramas, try one of these third party web viewers: To produce a virtual tour for iPad/iPhone/iPod you can use: If you don't have a web site, or one without FTP access, consider using one of the many dedicated panorama and virtual tour hosting services. The panorama can be uploaded to such a service and optionally embedded in your own website by means of an IFRAME. Most panorama viewers or panorama publishing services can handle 360 x 180 degree equirectangular images and this has become the de-facto standard for spherical images. If your panorama has sufficient coverage to be considered spherical, PTGui will automatically pick this projection. If not, select it by doing Panorama Editor -> Projection -> Spherical (360 x 180 Equirectangular).

It's also possible to publish a panorama to Facebook; see Q6.16.

If you would like to view a spherical panorama on your computer (not on a website) see Q6.29.
6.16. How can I publish a panorama to Facebook?
Facebook supports spherical panoramas, which are displayed in an interactive panorama viewer. The required 'gpano' metadata is embedded by PTGui by default, so it works with panoramas straight from PTGui.

You should create a 360 x 180 degree panorama in Equirectangular projection: in PTGui select Panorama Editor -> Projection -> Spherical (360 x 180 Equirectangular) and use the tiff or jpg output file format (because PTGui currently does not embed metadata in Photoshop output). Facebook apparently expects the width and height to be even, so a size of 8000x4000 pixels will work, but 8002x4001 may not work.
6.17. Why does Facebook display my panorama as a flat image, not as an interactive panorama?
For Facebook to recognize the image as a panorama the image should contain the 'gpano' XMP metadata. PTGui 10 and later embed this data by default; just be sure to use the proper projection and file format (see Q6.16). If the image from PTGui has been processed in an image editing application (like Photoshop, LightRoom, GIMP), it's possible that this has stripped out the metadata.

To verify if the necessary metadata is present upload your panorama to metapicz.com (or any other metadata viewer). You should see an XMP section containing the following:

ProjectionType       equirectangular
UsePanoramaViewer    1
(...)
StitchingSoftware    PTGui Pro 10.0.15 (www.ptgui.com)

If this section is missing (or even if the section is present but there is other nonrelated XMP data as well), Facebook will treat your panorama as a regular non panoramic image. Try to use an image straight from PTGui to ensure the problem is not caused by post processing.
6.18. How can I use PTGui to add the metadata required by Facebook to an already stitched panorama?
This can be done as follows: Please note that this re-processes the image, including interpolation and JPEG decompression and compression (if applicable). This will slightly degrade the image quality, although in practise this is probably hardly noticable.

The image interpolation step can be avoided by switching PTGui to Advanced mode (in the side bar), then go to the Create Panorama tab and choose 'Interpolator: Nearest Neighbour'. Note that Nearest Neighbour interpolation only gives good results if the generated panorama is completely identical to the source image (same projection, same pixel dimensions, no warping).

Do File - Save As Template to save the project as a template. This template can be applied to other equirectangular images (but only if they have the same pixel dimensions).
6.19. How do I level/straighten a panorama using horizontal / vertical line control points?
Besides straightening a panorama manually in the Panorama Editor, it's also possible to level a panorama using 'horizontal line' and 'vertical line' control points. Such control points indicate points that should end up on a horizontal or a vertical line in the panorama. PTGui is able to modify the orientation of the panorama in such a way that the horizontal / vertical line control points are aligned on a horizontal or vertical line, respectively, in the panorama.

Vertical line control points can be placed on any vertical feature in the panorama, such as the side of a building. Horizontal line control points should only be placed on the horizon itself: in a spherical panorama, all horizontal lines are curved, except for the horizon itself. For most panoramas (in particular cityscapes) it's easiest to use only vertical line control points. One exception would be a panorama of a sea shore: here you could place horizontal line control points on the horizon.

While regular control points can only be placed between two different images, horizontal / vertical line control points can be placed within the same image. To do so, choose the same image in the left and the right pane in the Control Points tab. The 'CP type to add' listbox sets the type of control point that will be created next. Choose 'horizontal line' or 'vertical line'. Then click on two points (one in the left pane and one in the right pane) that should be aligned horizontally or vertically. Even if the two points are within the same image, place one point in the left pane and one point in the right pane.

For most panoramas it's sufficient to place two pairs of horizontal line or vertical line control points, although it will not hurt to add more. The best results are achieved if the two pairs are in different parts of the panorama, preferably in a 90 degree yaw interval (e.g. one in northern direction and one in eastern direction).

Now there are two ways to have PTGui align the panorama based on the horizontal / vertical line control points:
  1. In the Panorama Editor menu bar, choose Edit | Level Panorama.

    PTGui will rotate and move the panorama in such a way that the horizontal / vertical line control points are aligned as much as possible. This is similar to dragging the panorama in the Panorama Editor in 'Panorama Edit' mode: since the panorama is moved as a whole, the alignment of individual images is not affected. Or:
     
  2. Use the optimizer by pressing the 'Optimizer' or 'Run optimizer' buttons.

    If the optimizer tab is in Simple mode (this is the default setting), or if in Advanced mode with 'Level in second pass' selected: PTGui will do a two stage optimization. First the images are aligned as usual based on the normal control points. The horizontal / vertical line control points are ignored in this step. In the second pass the optimizer levels the panorama as described above, using only the horizontal / vertical line control points. In other words, horizontal / vertical line control points are only used for levelling, and only the regular control points are used for aligning the images.

    If the optimizer tab is set to Advanced mode and 'Include in single pass' is selected, everything is optimized in one pass. Now the horizontal / vertical line control points will be used to optimize image alignment too. This can be useful in particular for straightening a single image based on horizontal and vertical features, but is not recommended for leveling panoramas. When 'Include in single pass' is selected, it is necessary to give the optimizer sufficient freedom by allowing it to modify the pitch and roll of all images (i.e. the pitch and roll checkboxes for all images should be checked). With 'Level in second pass', or with the optimizer in Simple mode this is not needed.
Be sure to watch part #8 of our Video Tutorial series.

6.20. How can I correct a single image for vignetting in PTGui Pro?
First you need to determine the vignetting of your lens. To do so, take a small panorama (e.g. 3 images, each overlapping about 50%). The amount of vignetting depends on the aperture of the lens so this should be done for each aperture at which you intend to do vignetting correction. In this calibration project, go to the HDR/Exposure tab and press Optimize Now. Press the Save buttons below the vignetting curve and the camera response curve to save the curves to a file.

The actual vignetting correction can be done as follows: You can save the thus created project to a file and use it as a template for subsequent corrections: you will only need to start a new project, load the next source image and choose Apply Template.

It's possible to combine this process with barrel distortion correction, see Q6.14.
6.21. My spherical panorama still has a hole in the top and/or bottom. How do I fill the missing parts to make the panorama truly spherical?
PTGui does not require your photos to be limited to a single row. To fill the missing parts just take additional pictures with the camera pointing upwards ('zenith') and downwards ('nadir') photos. As always you should make sure to rotate the camera around the 'no parallax point' (see Q5.4). This is even more important when shooting the nadir and zenith photos.

Start a new PTGui project and load all your images, including the nadir and zenith photos, before pressing Align Images. The order of the photos is not important, PTGui should be able to figure out which image belongs where in the panorama.

Sometimes PTGui is unable to find control points, and this may happen in particular with nadir and zenith images (for example if the zenith image contains mostly blue sky). In that case you will see a warning 'PTGui was unable to find control points for one or more images' in the Project Assistant. If this happens see Q4.4.
6.22. After running Publish to Website my panorama has black holes at the top and bottom; how do I get rid of these?
If you did not include a zenith and nadir image (with the camera pointed upwards and downwards, respectively) the top and bottom of the spherical panorama are not covered by images, resulting in black circular holes at the top and bottom. To hide these holes you can limit the vertical viewing angle by setting a minimum and maximum tilt angle in the Publish to Website window.

This will limit the amount in which the viewer can look up and down so that the black borders remain unvisible.
6.23. PTGui leaves some blank space around my panorama. How can I crop the panorama so that it fills the canvas entirely?
Cropping can be done in two ways:
6.24. How can I tell PTGui to output panoramas at a specific size?
First, in the Project Settings tab (PTGui Pro only): disable the checkboxes 'Fit panorama' and 'Choose a suitable projection'. Then go to the Panorama Editor and choose the desired panorama projection and field of view in the Projection sidebar. Finally, in the Create Panorama tab enter the desired output dimensions and select 'fix at ...% of optimum size'.

These settings can be re-used by saving this as a template using File -> Save As Template.
6.25. How can I defish a fisheye image in PTGui?
A fisheye lens distorts images such that straight lines become curved. Removing this distortion is typically called 'defishing'. Please note that it is not necessary to defish images prior to stitching, PTGui can perfectly handle fisheye source images.

Defishing is done by converting from fisheye projection to rectilinear ('flat') projection. A single image can be defished in PTGui as follows: Please note that it's typically impossible to keep the entire image. Fisheye lenses usually have a field of view of 180 degrees while rectilinear projection is limited to around 120 degrees. Attempting to get a wider view will result in extreme stretching of the corners of the image. In fact it is the fisheye distortion which allows a fisheye lens to have its wide field of view.
6.26. How can I extract a 'flat' image from a spherical panorama?
This is done by converting the panorama to rectilinear projection. The process is nearly identical to defishing (see previous question) and the same limitations apply.

Assuming your panorama is a 360 x 180 degree equirectangular image, proceed as follows: Again, flat projections are limited to about 120 degrees field of view; it's impossible to display an entire 360 degree panorama in rectilinear projection.
6.27. I have taken multiple panoramas from the same viewpoint, to create a time lapse movie. How can I ensure that subsequent panoramas are aligned when played back in sequence?
By default, for spherical panoramas PTGui will pick a random point on the horizon as the center point. If the first image of all your panoramas was taken in exactly the same direction, you can use the following method: Now the panorama is aligned around the same point in the first image.

Or, if all panoramas were taken from the same viewpoint but not exactly in the same direction: First stitch the first panorama in the normal way. Create a medium sized copy of the panorama in jpeg or tiff format, we will use this to align the subsequent panoramas against. For each subsequent panorama: For time lapse movies Optimum Seam Placement should be disabled, this can be done in the Blending side bar in the Panorama editor. With Optimum Seam Placement, the seam would be placed at a different position in each frame.
6.28. My project contains one or more images without any recognizable detail and it's impossible to place control points. How can I stitch my panorama?
Sometimes one or more images in a panorama don't show any suitable objects to place control points on, for example when an image contains only blue sky or a plain white wall. Since the exact alignment of a plain colored image is usually not critical, you can align it by hand:

First make sure that the rest of the panorama is set up properly (usually just pressing Align Images is enough). Then go to the Panorama Editor window by pressing Ctrl+E (Windows) or Command+E (Mac). Switch the panorama editor to 'Edit Individual Images' mode using the toolbar, the menu or by pressing Ctrl+Shift+I (Windows) or Command+Shift+I (Mac). In this mode you can move individual images around. Use the left mouse button to move an image, or use the right mouse button to rotate it. Single button Mac users can use Ctrl+Mouse button to rotate. For more information see the Help page for the panorama editor pressing F1 (Windows) or Fn+F1 (Mac).

When done, go back to the main window, click on Optimize and proceed to Create Panorama. You can ignore warnings about missing control points.
6.29. How can I view a finished panorama interactively on my computer?
To view a spherical panorama interactively (i.e. with the ability to 'look around' by clicking and dragging the mouse) you need a panorama viewer. Since version 10 a spherical panorama viewer is included with PTGui.

For interactive viewing the panorama should be stitched as a 360x180 degree equirectangular image. To choose this format select Projection - Spherical in the Panorama Editor menu bar in PTGui.

To view your stitched panorama interactively, press the 'View...' button in the Create Panorama tab and select 'Open in PTGui Viewer'. The PTGui Viewer can also be opened directly via Tools - PTGui Viewer. The PTGui Viewer supports panoramas in equirectangular projection, in TIFF or JPEG format.

Other panorama viewers are available as well: For more viewers see Panorama Viewers (PanoTools.org Wiki).

For many years Apple's QuickTime Player has been able to display interactive spherical panoramas through a special type of .mov file called QuickTime VR (QTVR). Unfortunately Apple decided to remove QTVR support in 2009, so QTVR should be considered a legacy format. See Q4.9 if you need to play a QTVR .mov file .

PTGui can be configured to launch one of these viewers when the Preview button (in the Preview tab) or the View button (Create Panorama tab) is clicked. To configure this go to Tools-Options (Windows) or PTGui-Preferences (Mac). In the Viewers tab enter the path to the viewer application. Up to 3 applications can be configured: not only panorama viewers but also image editing applications such as Photoshop.

If you would like to embed a spherical panorama on your website see Q6.15.
6.30. I would like to send a panorama to a friend/client/... Is it possible to view a panorama interactively without needing to install a plugin first?
No, unfortunately no such format exists. The panorama can be saved in a regular image file (jpg for example) and then viewed in a panorama viewer application. One such a viewer is FSPViewer, which is free and runs on Windows, macOS and Linux. FSPViewer can display panoramas saved by PTGui in the 360° x 180° equirectangular format. For other options see Q6.29.

Alternatively publish the panorama to your website, on most computers it will be possible to view the panorama without needing to install anything. See Q6.15.
6.31. I need to align/overlay an image to an already stitched panorama. How can I do this?
This can be done as follows:
Keep in mind that as with any panorama, parallax errors will prevent proper stitching. Therefore the image to be overlaid should be taken from exactly the same location as the original photos for the panorama.

If you need to do the same for multiple panoramas or overlay images, you can save some time by using templates. Use File - Save As Template to save the settings of the project to a template, and use File - Apply Template to apply the settings to a future project. Control points still need to be placed by hand though since they are specific to the images used.
6.32. How can I stitch a PTGui project from the command line?
PTGui supports two methods for command line stitching: the '-batch' flag adds project files to the batch stitcher queue for background stitching; the '-stitchnogui' flag stitches a project in a command line window without showing any windows.

Use the -batch flag as follows:

On Windows:
"C:\Program Files\PTGui\ptgui.exe" -batch "C:\Path\To\Projectfile.pts"

On macOS use the open command as follows:
open "/Applications/PTGui Pro.app" --args -batch "/Path/To/Projectfile.pts"

On Linux:
/path/to/PTGui -batch /path/to/projectfile.pts

The above command returns immediately. The '-x' parameter can be added (after -batch), this causes the batch stitcher window to close when stitching has finished.

The second method stitches the project on the command line, without using the batch stitcher, and blocks until rendering has finished.

On macOS launch as follows:
"/Applications/PTGui Pro.app/Contents/MacOS/PTGui Pro" -stitchnogui project1.pts project2.pts batchlist.ptgbatch

On Windows:
START "" /WAIT "C:\Program Files\PTGui\PTGui.exe" -stitchnogui project1.pts project2.pts batchlist.ptgbatch

On Linux:
/path/to/PTGui -stitchnogui project1.pts project2.pts batchlist.ptgbatch

If configured the batch stitcher can also align the images and generate control points (Pro version only). To do so enable 'Align images and save the modified project' at 'Batch Stitcher actions' in the Project Settings tab. This allows for fully automated batch stitching of images without user interaction.

Note that on Linux, PTGui currently requires a valid $DISPLAY even when used with the -stitchnogui flag. As a workaround you may create a dummy graphical desktop using VNC server and let PTGui use this. We hope to solve this in a future update.
6.33. Can I use PTGui to arrange pictures into a collage? Can I disable the warping/distorting of images?
Yes this is possible. The trick is to simulate using a long (narrow angle) lens, in this case hardly any warping will be done. Also, PTGui needs to be told not to optimize the lens field of view or lens distortion. To get an unblended collage you need to choose layered Photoshop output and flatten the panorama in Photoshop.

In short:
6.34. How can I stitch panoramic video in PTGui?
PTGui does not directly support stitching of video footage. But the Batch Builder can be used as a rudimentary tool for stitching video. To do so, the videos first need to be converted into individual JPEG or TIFF frames using a suitable third party video editing application. Stitch the first frame as a regular panorama in PTGui and save the project file. This project file can be used as a template in the batch builder so that all subsequent frames are stitched exactly like the first. The resulting panoramas need to be assembled into a video in a video editing application.

Optimum seam placement should be disabled in the Blending side bar of the panorama editor. Otherwise the seams will be placed differently in each video frame.

To learn more about the batch builder, choose Tools - Batch Builder in PTGui Pro and press the Help button there.

For a dedicated panoramic video stitcher see SGO Mistika VR, this supports stitching based on a PTGui template.
6.35. Is there a way to stitch many panoramas using the same settings?
Yes, PTGui Pro includes the Batch Builder for this purpose. The Batch Builder scans a chosen folder for images and creates project files automatically. The project files can be based on a custom template. Once the project files have been generated they can be stitched overnight using the Batch Stitcher. If needed, control points can be generated as part of this process. Or, if the camera positions are known, control point generation can be skipped and all panoramas stitched with exactly the same settings.

For more information, launch PTGui Pro, go to Tools - Batch Builder and click on the Help button.
6.36. How can I make 'little planet' images in PTGui?
A little planet is a panorama projected such that the floor of the scene is in the center. By using a stereographic projection, the horizon of the scene will become circular, thus giving the impression that the photo was taken from above a small planet.

A the little planet image actually is a fully spherical panorama since it covers both the floor (nadir) and the sky (zenith). Just like a regular spherical panoramas it is most easily taken with a fisheye lens.

To create a little planet panorama load your source images in PTGui and press Align Images. Then go to the Panorama Editor side bar and choose Projection -> Presets -> Little Planet.

Also see: Projections.
6.37. How can I stitch images from Adobe Lightroom in PTGui? Do you offer a Lightroom plugin?
Currently we do not offer a plugin for Adobe Lightroom, but PTGui can be integrated in Lightroom as an external editor as follows:

Now you can open your photos from Lightroom into PTGui as follows: in Lightroom's library view select the photos to be stitched, right-click (Ctrl+click on Mac) on the selection and choose Edit In - PTGui. Then if you want to stitch the original photos choose Edit Original (note that PTGui will only read and never modify your source images). Or to stitch the photos with any Lightroom adjustments choose Edit a Copy with Lightroom Adjustments.

After the panorama has been stitched in PTGui, go to the folder in Lightroom's library where PTGui has created the panorama, right click on the folder name and choose Synchronize Folder. This imports the stitched panorama back into Lightroom.
6.38. Can you tell me how to make 3d (stereoscopic) panoramas in PTGui?
It might look easy at first sight (just stitch two panoramas, one for the left eye and one for the right eye), but stitching stereoscopic 360 degree panoramic images is actually far from trivial. Image alignment will not be perfect and it's impossible to get a true 3d view at the nadir and zenith using only a single panorama per eye.

The reason is parallax: to stitch seamless panoramas one needs to get rid of any parallax (see Q5.4). On the other hand parallax is a requirement for stereoscopic images: it's the parallax caused by the distance between our eyes that allows the brain to sense depth. Therefore any attempt to create a stereoscopic panorama will be a compromise between perfect image alignment and getting 3D depth.

That said, several people have developed techniques for stereo panoramic stitching. All methods come down to taking many images at small yaw increments (say 10 degrees). The camera is deliberately placed away from the no-parallax point. Due to the small yaw increments only a narrow slice of each image is used and this prevents the parallax error to accumulate over a wider area. In other words there will be many stitching errors but they are small and perhaps even unnoticeable.

Getting a stereoscopic view of the nadir and zenith remains impossible though. Imagine looking at the nadir and zenith while rotating the view: the panoramas for the left and right eye would gradually need to swap when the viewer rotates from 0 to 180 degrees, and intermediate views would be needed for the viewing angles inbetween. This is impossible to do with just a left eye and right eye panorama. But if the zenith is just plain blue sky and the nadir a flat surface one may get away without stereoscopic depth in these areas.

Tom Sharpless' method works well with the optimum seam placement features of PTGui Pro 12.

Many years ago, Wim Koornneef developed an easy workflow for creating stereo panoramas with PTGui: Revised version of the tutorial "How to make a spherical 3D panorama with a single camera and a fisheye lens".

Also see this thread at the PTGui support forum: Managing stitching for stereo and Jim Watters' video tutorial: Stereo Stitching with PTGui.

If you would like to discuss 3D panoramic stitching please join the PTGui support forum!
6.39. How can I stitch two back-to-back circular fisheye images?
First of all, if possible (i.e. when using a single camera on a rotating panoramic tripod head), it would be better to use 3 images (spaced 120 degrees apart) instead of 2 images back-to-back. With 3 images there is much more overlap, PTGui will be able to align the panorama fully automatically and and the larger overlap area allows the blender to make smoother transitions between the. But if you must use two images, read on:

The difficulty when using two circular fisheye images back-to-back is the small overlap area: the images overlap only in a small ring at the outer edge of the images. This ring usually too small for PTGui to be able to find control points, so you will need to place control points manually. Also due to the small overlap area PTGui is not able to determine the lens distortion accurately. Therefore proceed as follows and create a template for your setup:

Assuming the result looks good, save it as a template using File -> Save As Template. For the next panorama most of the above steps can be skipped. Instead use the template by starting a new project, loading the two images and choosing File -> Apply Template -> and browse to the saved template. If the panorama needs better alignment, add control points and run the optimizer. If it looks good already, just skip the control points and go straight to Create Panorama.

If the photos were taken with two cameras back-to-back (as opposed to a single camera on a rotating tripod head), keep in mind that there will be parallax and the panorama will have stitching errors. See Q4.10.
6.40. How can I retouch the nadir of a spherical panorama?
Often it's necessary to retouch the nadir (the floor) of a spherical panorama, in order to get rid of the tripod or to remove small stitching errors. Retouching the nadir can be done in several ways; it's easiest to do the edits in cube faces images.

For the reconstruction to work, the cube faces must retain their file names. PTGui recognizes which image is which cube face based on the file name. The default naming (.front.tif, .right.tif, etc) can be changed by clicking the Cube Face Naming button in the Convert to Cube Faces dialog.
6.41. How can I stitch images taken with a 360° one shot camera in PTGui?
Several single shot 360° panoramic cameras exist, producing a single image containing two circular fisheye images side by side. PTGui supports several of these cameras, including the Samsung Gear 360, Xiaomi Mijia Mi Sphere, Yi 360 VR and Ricoh Theta Z1. If an image from such a camera is loaded into PTGui, PTGui will actually add the same image to the project twice, with different cropping circles and masks, positioned at -90 and +90 degrees yaw.

While this already results in a roughly stitched image, the images still need to be aligned for perfect stitching. This is due to small differences between individual cameras of the same type, resulting in different small offsets of the image circles. You only need to perform manual alignment once for each camera, the result can be stored in a template and re-used. To create the template:

For subsequent images the template can be used instead: Load a picture from the 360° camera, then do File | Apply Template and select the template created above. The images are aligned already and the panorama can be stitched by going straight to Create Panorama.

The template can also be used for batch conversion using the Batch Builder (PTGui Pro only):
 Keep in mind that all cameras with multiple lenses will produce images with parallax. Some stitching errors will be unavoidable, especially in small rooms or with objects close to the camera. Also see: Q4.10
6.42. How can I prevent PTGui from placing control points in certain areas?
Sometimes it can be useful to exclude certain areas of images from having control points added to. For example clouds in the sky: these may have moved significantly between shots. Or the panoramic tripod head might be visible in the images (and it has been rotated). Any control points placed on moving objects will cause misalignments in the stitched panorama.

The control point generator in PTGui Pro ignores any red masked areas, so the solution is to go to the Mask tab (Pro version only) and paint the areas to be exluded with a red mask. Then run Align Images to generate control points. Red masked areas will also be excluded from the stitched panorama; if this is unwanted, the masks must be deleted again. To delete all masks go to the Source Images tab; press Ctrl+A (Windows) or Command+A (Mac) to select all images. Right click (or Ctrl+Click on mac) to open the context menu and select Clear Mask.

If the same masks can be re-used for future panoramas, save the project with masks to a template using File | Save Template.
6.43. We are trying to parse a PTGui .pts project file. Can you explain how the lens parameters are stored?
Parsing crop and lens shift from a PTGui project file is slightly complicated. This is because PTGui stores it in such way that the same data can be used for images in portrait and landscape orientation, and for any image size. We've created a javascript demo to demonstrate how to parse the lens data from a PTGui project file.
6.44. How can I rotate individual images? The rotation buttons in the Project Assistant tab only seem to rotate all images together.
For stitching a panorama it's not necessary to rotate individual images. PTGui will figure out how the images overlap; it will rotate all images as required. Rotation of the individual images is performed by adjusting the 'roll' angle. See the Image Parameters tab (in Advanced mode).

The rotation buttons in the Project Assistant rotate the panorama as a whole in steps of 90 degrees. This can be done even after aligning a panorama; the alignment of the images is not affected.

The orientations of the thumbnail images in the Project Assistant reflect the orientation of each image in the complete panorama. If a source image appears in the panorama approximately in portrait orientation, it will be shown in portrait orientation in the Project Assistant. If you rotate the panorama 90 degrees in the Panorama Editor, all thumbnails will change orientation automatically.

In the Mask tab, Crop tab and Control Points tab, the same automatic rotation is used, but here you can override the orientation by pressing the rotation buttons below the images. Press the A button to switch back to automatic image rotation.

Also see Q4.5.
6.45. I have 6 cube face images. How can I combine them into a panorama?
The easiest way is to rename your images such that they have names like this (xxxx can be anything):
Start a new, empty PTGui project and load the 6 images. If the images are square and have the above name suffixes then PTGui will automatically recognize them as cube faces. After loading the images go straight to the Create Panorama tab and create the panorama. You'll now have the retouched panorama in a file named '...Reconstructed.tif'.

The default naming (.front.tif, .right.tif, etc) can be changed by clicking the Cube Face Naming button in Tools - Convert to Cube Faces.

Also see Q6.40.
6.46. How can I align a panorama against a reference image?
If you have an image (or panorama) of the same scene, you can use it as a reference image. The reference image will be used as a guide for aligning the individual images of a panorama. The reference image will not be included in the final panorama.

Proceed as follows:
Please understand that the reference image must have been taken from exactly the same viewpoint, otherwise parallax errors will occur and perfect alignment is not possible.
7. PTGui Pro and HDR

7.1. What is the best way to take images for HDR stitching in PTGui Pro?
Disable all automatic features of your camera, except for automatic bracketing. In particular:
7.2. My images don't contain EXIF exposure information. Can I still use them to stitch HDR panoramas?
Yes, just enter the exposure data in the Image Parameters tab. At least the exposure time should be filled in for each image; the aperture and iso fields can be left blank. Switch PTGui Pro to Advanced mode to make the Image Parameters tab visible.
7.3. PTGui Pro doesn't recognize my bracketed exposures!
See: Error: No HDR exposure sets found
7.4. PTGui Pro displays the wrong EV values! My images were taken at -2, 0, +2. This is confirmed by the EXIF data but PTGui shows something else in the Image Parameters tab.
The Exposure Value (EV) recorded in the EXIF data (in the Exif 'exposure bias' field) indicates the difference between the actual exposure and the optimum exposure as measured by the camera's light sensor. In other words, it's the exposure offset the camera was instructed to use. It is not an absolute value and does not tell the actual amount of light captured.

On the other hand, the EV shown in PTGui Pro (Image Parameters tab) is calculated from the actual exposure data (exposure time, aperture and iso). This is the data that is used when generating HDR. The EV is a relative value, which can have an arbitrary offset. PTGui Pro offsets the EV such that the lowest EV equals zero minus the highest EV (i.e.: low = -high).

A difference between the displayed EV and the recorded EV can have two reasons: If you used auto bracketing in auto exposure mode, the camera has likely adjusted the base exposure time between each set of bracketed shots. In that case the bracketed sets themselves have an exposure offset within the panorama. A second reason is the limited choices of exposure times. For a +1 EV offset from 1/15s, most cameras will use 1/8s instead of 1/7.5s. The actual offset in this case is +0.9 EV.
7.5. What does linking images do?
In PTGui Pro images can be linked. This tells the stitcher to treat the images differently: linked images will be combined to HDR, or merged using Exposure Fusion, instead of regular panoramic blending. If bracketed images would not be linked, the blender would take non-overlapping parts from each bracketed image and try to blend the parts together, which will probably not give the desired result. Linking the images can be done using 'Link HDR Bracketed exposures' in the Images menu, or by selecting a number of images in the Source Images tab, right clicking and choosing 'Link Selected Images'. PTGui treats a set of linked images as if they are a single image. Use the little triangle button in the Source Images tab to switch between displaying linked images as a group, or as individual images.

Additionally, the poitions of each of the bracketed images can be linked, or remain unlinked. If the positions are linked, each of the bracketed images will have the same yaw, pitch, roll and viewpoint parameters. If the positions are not linked, the bracketed images will have their own yaw, pitch and roll. Control points should be provided in such a case in order to align the bracketed images. Linking the positions can be done in the Image Parameters tab using the 'Link' checkbox.
7.6. Can I retouch an HDR panorama, e.g. to remove ghost images of moving people?
This is possible by creating a layered HDR panorama in PTGui Pro: PTGui will create a layered document with the blended panorama in the bottom layer. On top of that are the individual blend planes. Each blend plane corresponds to the stitched panorama at one exposure level. The blend plane layers have a blend mask which is initally black. By painting with a white brush in the layer mask you can selectively reveal parts of the blend planes.

For details see the Post Processing tutorial.
7.7. I would like to stitch my panorama in PTGui Pro, but use another application (e.g. Photomatix or Photoshop) to create the HDR.
It's not necessary to use external applications since PTGui Pro can create HDR files. But if you prefer to use an external tool for merging to HDR, there are two ways to do this:
7.8. Can I use PTGui Pro for exposure fusing / tone mapping / HDR generation of non-panoramic images?
Yes, this is possible. But keep in mind that PTGui was originally designed for creating panoramas and you need to adjust some settings to make this work.

If your images were taken from a tripod and are already aligned perfectly:
  1. Start a new project in PTGui Pro
  2. Click on the Advanced button in the side bar to switch to Advanced mode
  3. Click Load Images and open your set of bracketed images
  4. Go to Source Images, select all images, right click and select 'Link Selected Images'
  5. Go to the Panorama Editor by pressing Ctrl+E (or Command+E on Mac)
  6. Choose Edit -> Fit Panorama. On Mac choose Panorama Editor -> Edit -> Fit Panorama. Now the images should fill the entire output area.
  7. Depending on which is desired, enable Exposure Fusion or Tone Mapping. This can be done in the side bar of the Panorama Editor window.
  8. If necessary adjust the output settings in the Create Panorama tab
  9. Finally press Create Panorama to render the output files
If your images were taken handheld they need to be aligned first. Proceed as follows:
  1. Start a new project in PTGui Pro
  2. Click on the Advanced button in the side bar to switch to Advanced mode
  3. Click Load Images and open your set of bracketed images
  4. Go to Source Images, select all images, right click and select 'Link Selected Images'
  5. Go to Image Parameters and uncheck the 'Link' checkbox for all images. This can be done by double clicking the header field above the first checkbox. Unlinking the positions tells PTGui that you want to align the bracketed images individually.
  6. Choose Control Points -> Generate Control Points
  7. Go to the Optimizer tab. Disable 'Optimize lens focal length' and select 'Minimize lens distortion: No'
  8. Press the Run Optimizer button at the bottom. This aligns your images.
  9. Proceed with step 5. in the above paragraph
You can save the project as a template using File -> Save as Template. The template can be used again (by choosing File -> Apply Template) for subsequent projects with the same setup (i.e. the same number of brackets, same camera and same lens). If the images are taken handheld, control points need to be generated for each project: repeat the steps 4-7 after the template has been applied.
7.9. Can I extract artificial bracketed images from my (non bracketed) RAW files and have PTGui Pro assemble those into an HDR panorama?
Yes this is possible, but there is no benefit in doing so. The purpose of generating HDR images is to overcome the limited dynamic range of a camera's imaging sensor. Suppose you are photographing a scene with both very dark objects and very bright objects: the dark objects will be close to the sensor's noise level: if you attempt to reveal dark objects by brightening the image in (e.g.) Photoshop, the noise will be amplified too so the dark objects will drown in image noise. Similarly, bright objects may be brighter than the maximum brightness that can be recorded by the sensor and thus completely white (this is called 'clipping'); darkening the photo will not reveal bright clipped objects anymore. To overcome this you take multiple photos of the same scene at different exposure levels. The HDR software (PTGui Pro) will take the 'best' pixels from all photos, i.e. those pixels that are not noisy and not clipped.

It's possible to do 'pseudo HDR' by extracting multiple exposures from a single RAW image, but all exposures will still suffer from the same limited dynamic range of the original RAW image. Hence the brighter exposure will be noisy and the darker exposure will not reveal any detail that was clipped. If you assemble these exposures again into an HDR image you will just end up with an image identical to the original RAW file, only in a different format.

Typically a RAW image has a dynamic range of 12 or 14 bits. No detail will be lost if you convert the RAW image to a 16 bit TIFF file as long as you make sure that no highlights are clipped. I.e. make the TIFF file dark enough until you see as much detail in bright objects as is available in the RAW file. Then stitch those TIFF files in PTGui.

Don't confuse HDR and tone mapping: what is typically referred to as the 'HDR look' is actually the result of tone mapping. You don't need bracketed images in order to do tone mapping; in PTGui Pro go to the Exposure/HDR tab and enable the 'Tone Map Stitched Panorama' checkbox.
7.10. I have read the previous answer but I still would like to stitch my pseudo bracketed images generated from RAW files!
When generating HDR images PTGui will look at the exposure settings in the EXIF data of the images to determine which images belong to a bracketed set. Normally the camera sets the proper exposure data in the EXIF header, but when extracting multiple images at different brightness from a single RAW file, all images will still carry the original EXIF data despite the difference in exposure.

To overcome this you need to override the the EXIF exposure data in the Image Parameters tab in PTGui Pro. For example if your original image was taken at a shutter speed of 1/200s but the exposure was boosted by +1EV this effecticely simulates an exposure of 1/100s. EV is a logarithmic scale: +1EV corresponds to a doubling of exposure time; +2EV is a quadrupling of the exposure time, +3EV multiplies the exposure time by 8, and so on.

Once you have entered the artificial exposure times for all images in the Exposure column in the Image Parameters tab, PTGui Pro should recognize your bracketed images if you do Images -> Link HDR Bracketed Exposures.
7.11. The brightness or contrast in the Detail Viewer differs from the stitched panorama!
Please see Q4.16.
8. GPU acceleration

8.1. Which GPUs are supported by PTGui?
To use GPU accelerated stitching a graphics card supporting OpenCL 1.1 is required. Do not confuse OpenGL and OpenCL, they are different technologies. PTGui requires 512 MB of graphics RAM but at least 2GB is recommended and will result in faster stitching.

GPU stitching is optional, a supported GPU is not required for running PTGui. If no suitable GPU is found PTGui will be fully functional, it just means that the CPU will be used for stitching.

Windows
Apple Mac
An Intel mac with a dedicated AMD or NVIDIA GPU is required, or a mac with Apple Silicon (M1) processor. Many older models only have Intel integrated graphics (Intel Iris or HD Graphics); this is not supported for GPU acceleraton by PTGui. OpenCL 1.1 is required, Mac models released before 2010 only have OpenCL 1.0.

Unfortunately Apple have decided to deprecate OpenCL. While it is still supported in the current macOS, Apple may decide to remove OpenCL from future macOS versions. This means that PTGui's GPU acceleration may no longer be available under some future macOS version. Apple is suggesting that developers rewrite their software to support Apple's proprietary Metal framework but this involves a huge amount of work. We can't say if or when PTGui will support Metal-based GPU acceleration.

Again, GPU acceleration is completely optional, it only serves to speed up the rendering of panoramas.
8.2. Which graphics card should I buy?
When looking for a GPU to upgrade your Windows or Linux desktop computer the following factors are relevant: A detailed overview of GPU chipsets can be found on Wikipedia:
List of Nvidia graphics processing units
List of AMD graphics processing units

A basic guideline would be to get a recent NVIDIA or AMD card with 4 GB of memory and as many CUDA Cores or Stream Processors as your budget allows.

Note that other components of the computer are just as important: in particular be sure to have enough RAM installed (16 GB or 32 GB for larger panoramas), and use SSD drives instead of spinning hard disks for temporary storage, input and output images.
8.3. Does PTGui support using multiple GPUs?
No, PTGui will only use one OpenCL device for GPU accelerated stitching. Also, linking multiple graphics cards via NVIDIA's SLI or AMD CrossFireX will not work: the cards will still appear as two separate OpenCL devices to the system.
8.4. PTGui reports 'no supported GPU device available' even though my (Windows) computer has an NVIDIA GPU supporting OpenCL.
Under some circumstances the NVIDIA GPU driver may become installed with OpenCL support missing. We haven't figured out why or how this happens, but it can be resolved by performing a clean installation of the latest NVIDIA GPU driver. This can be done as follows:After restarting PTGui, your GPU should be visible under Advanced - GPU Acceleration.
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