When assembling HDR panoramas it's important to link the bracketed images. Bracketed images must be merged to HDR, instead of blended (like the regular source images of a panorama). By linking the images, PTGui will know which images belong to a bracketed set.
PTGui attempts to automatically link your source images by looking for a repeating exposure sequence in your images. This only works if each bracketed set has the same number of exposures, and the exposure sequence is strictly repeating. For example:
- 1/200 s
- 1/50 s
- 1/400 s
- 1/200 s
- 1/50 s
- 1/400 s
- ...and so on
If you cannot figure out what's wrong, take a look at the actual exposure data in the Image Parameters tab.
Switch PTGui Pro to Advanced mode to make the Image Parameters tab visible. In the Image Parameters tab, click the triangle (▶) to expand the table to show the individual bracketed images. The table shows the Exposure Time, Aperture and ISO value as found in the metadata. Note that these values can be edited: if the data was missing you can enter the correct values here. The three values together determine the actual exposure level of the image. This exposure level is calculated and shown in the EV column. Verify that the EV column shows a repeating sequence.
Generally it's advisable to use manual exposure mode (the M mode on your camera) and use the Automatic Exposure Bracketing (AEB) function of the camera to vary the exposure time. This way the aperture and ISO value will be the same for all images, and each bracketed set will use the same series of exposure times. Automatic exposure mode (Av or Tv) will also work for PTGui Pro 12 but not in earlier versions. For images taken in Av or Tv mode, the exposure times will be different for each bracketed set (depending on the brightness level) but PTGui may still be able to determine the bracketing sequence by inspecting the 'Exposure Bias' EXIF fields. This value is not shown in the Image Parameter table though.
If PTGui fails to automatically detect bracketed exposures, or if you used irregular bracketing on purpose, PTGui can still stitch your panorama. You just need to tell PTGui which source images belong to the same bracketed set. In the Image Parameters tab, select the images that belong to the same bracketed set, right click and choose 'Link Selected Images'. Repeat this for each bracketed set.
If you can't figure out why PTGui fails to detect your bracketed images, just post a message to the
PTGui support forum and attach your project file. We'll help you out.