Perspective correction and crop

DT 3.0.2 on Manjaro KDE

I took some interior photos with a Fuji XF 16mm f/2.8, on tripod, with a wireless remote.

I wanted to make sure that the verticals are straight:

  1. Enabled lens correction
  2. Perspective correction
  • automatic cropping largest area
  • lens model generic
  • get structure |||

Then I click on the automatic fit just above the |||.

then exported the images as tiffs. Every file is a different size (pixels):

  1. 5274x3978
  2. 5698x3965
  3. 5645x3962
  4. 5707x3983
  5. 5721x4007
  6. 5684x6895

Now in Gimp, I can align the layers but I did not touch the tripod. Should they all be identical in size?

Is this a DT bug? or an operator error (me) in DT? or an operator error (me) while taking the photos?


If you took the photos from the same place into the same direction the perspective is unchanged - so a perspective correction should calculate the same correction Parameters for all. I would expect slight differences, but an exact match eis even better :wink:
So if everything is ok you should be able to align them In gimp.

But in that case images 1. and 6. are strange, in that the size is way out of the range of 2.-5.

  1. I can align them in gimp ==> I’m OK
  2. What I don’t understand is why DT gives me a different result for every image by as much as 424 pixels between #1 and #2 and 447 between 1 and 5

BTW oops: #6 should read: 5684x3985 in my original question


Even slight differences in the parameters can cause different dimension of the rotated and sheared image and autocrop will likely give different results.

Better yet: if you’re sure the images should have the same corrections because they were taken without moving the camera, do the automatic fit on one and just copy the module parameters to the rest.

I think it is possible for it to get distracted if the contents of the image are slightly different, or an effect of one of the modules is slightly different. The last point is key: the algorithm could be too sensitive to certain elements; e.g. CA correction (not confirmed, just an example).

Last time I encountered a problem, the culprit was AMaZE. When I switched to another demosaicing method, the auto correction was more reliable. Lastly, I recall there being a revision in the works. I haven’t checked the status of that endeavour.

Best solution is to export the images prior to any size or perspective modification … you can always come back later and define thhe final shape/size

I just enabled the lens correction first, then applied the perspective correction.

These files are from a Fuji x-pro2 with Fuji XF 16mm f/2.8 demosaiced with Markestejin 1-pass.


The lens correction should be the same for all photos, if no parameter changes, you should get the same result.
But, the perspective correction tries to find structures in the image to do it’s correction. So, from one image to the other, the detected structure can change and the applied transformation changes.
To solve your problem, you should apply the same set of transformation to all images.
The workflow should be:

  1. Take a reference picture in your set
  2. On that picture, apply the lens and perspective transformation
  3. In the light room, select that picture, and via the history stack module copy the lens and perspective correction modules
  4. In the lightroom, select all pictures of your set and paste the lens and perspective modules.
  5. Retouch all images as you which.
    This process will ensure that all images are processed with the same transformations and all of them should end with the same size.

Will do

Thank you