an other problem with panorama stitching and highlight recover
I found an other problem which happens in the stitching panorama tool.
I am making a panorama from 8 vertical pictures taken with my Sony A1.
I selected the 8 pictures with out making any adjustment on the single image and build the panorama. As the pictures were taken hand held the final panorama obviously has some black around the image which need to be cut.
The problem happens if I try to recover the high lights; as you can see in the attached files, near the edge of the picture it creates a strange halo as if the black parts (introduced by C1) where parts of the final image.
Those halos remain even if the resulting panorama is cut to eliminate the black parts.
I tried to recover the high lights on every single file before the stitching but, while all the single pictures are perfect, after the stitching the final result is identical.
In the first picture you can se a screenshot to show how the halo appear while in the second picture I exasperate the contrast to make them more visible.
Best regards
Lorenzo Ceva Valla
-
The problem has nothing to do with the number of the picture used for the panorama stitching and also it has nothing to to do with light fall-off but with the high light recover.
To understand what I mean think first to a single image (for example a mountain view from a window so with a very dark frame in the picture it self) in this case if you try to recover the high light of the mountain view heavily you will obtain the same halos which i showed in my panorama near the darkest parts of the picture. Note that those halos remain even if you cut the image to completely exclude the dark frame of the window. This happens because the high light recover takes in count the part of the image that has been cut.
When you do a panorama stitching C1 creates some black zone to "compensate" the inexact position of the camera between the different shoots. The problem is that C1 consider those black zones as a part of the image and when you apply the high light recovery you get the same effect (unacceptable halos) you get with a single image as I mentioned before.
The proof of what I am saying is that if I do the high light recovery on the single image of the panorama everything works perfectly because in the single image there is not any black frame (window for example) but if I use those corrected images to build the panorama the halos are just the same as if the recovery was done on the final panorama.
So if I can accept that C1 makes some halos when the characteristics of my image are responsible I can't accept that the halos are there because C1 "changes" my image by adding some black and considering those parts as part of the picture.
So the solution must be found by changing the way C1 works: It would be nice if C1 normally consider only the final cut image for the high light recovery (as it works for example with vignetting) but it is a must that C1 do not consider the black zone created by it self in panorama stitching as a part of the final image.
I hope I explained better my point of view.
Best regards
Lorenzo
1 -
I think I am having the same problem. See the dark shadow in the center of the 3 picture pano. Any thoughts?
I should also comment that I stitched these same three photos in LR and no artifact. Still prefer C1...
0 -
Scott, the dark segment of a circle looks like a lens vignette can probably be removed or at least mitigated if you adjust the source images with the lens correction light falloff, try the C1 profile but also the manufacturer profile. I have similar results as you and the C1 profile was worse than the manufacturer profile with even with the max setting of 120.
Lorenzo, this is not a solution for your horizontal darkening, but might be for the diagonal circle segments.
As far as I know the lens correction is the only adjustment which makes it into the dng.
0 -
Hi BeO
Thanks for taking the time to address my question. You were right, once addressing the light falloff all is well. Great community here and I appreciate your willingness to share your experience and knowledge. Happy Holidays.
0 -
Lorenzo,
If you reselect the images and use, say, 5 or 6 of them rather than 8 AND consider the light fall-off adjustments mentioned above, does that give you a better result?
The test images I have used do not seem to have any light fall-off issues but using more images than was really required (especially when shooting hand held) seemed to be a little more problematic and, in the end, unnecessary. Better result and less processing time seemed like win.
0 -
Lorenzo,
You have other issues that would be addressed by the lens corrections and likely reduce the effects you are seeing.
You would have fewer joins and possible, but not certainly, fewer dark edges.
There is no way I have found to successfully handhold a multishot pano with needing to crop the result to remove edges.
If you would prefer to use a pixel editor to fill in the black sections that's fine and should allow the replacement of the white edges as part of the blending process that would likely be necessary anyway.
The problem you have described seems to relate to any image not specifically the stitched result. The results you are showing look a bit extreme even for highlight recovery. (More like halos from sharpening?)
Vignette works, if you choose, to the crop rather than the source image. You can achieve the same result for any tool where the adjustments are applied by using a layer and applying a mask that will only make changes to the content overlaid by the masked area.
Have you tried that already?
0 -
I agree as I said the problem is a natural consequence of the normal behavior of C1. The difference is that in this case the black parts are made by C1 and not by me. I wonder if it would be possible to modify C1 to "convince" C1 to internally consider the black parts as not part of the image as if those parts were on a different level.
Make those parts white will solve the problem for high light recover but it could introduce the opposite effect on dark parts of the picture in case of shadows recovery!
Working on a different layer masked to exclude the black parts does not solve the problem on the panorama as it does not solve the problem on a single picture.
C1 still consider the masked parts of the picture as a part of it in the same way it behaves when you normally cut the image.
To use a High light recovery efficiently I must stay on the RAW file in C1 there for using a pixel editor is not an option!
Up to now the only way to solve this problem is to correct every single picture, export them and build the panorama in an external software just as I did till capture 22. Not very happy about it!
PS
No sharpening is applied to my image and the lens correction tool is used with the correct profile on each picture as I always do!
0 -
In 15.0 only the lens correction tool was respected. Not the vignetting tool, to my knowledge.
They have made some improvements, do you use the latest version 15.1?
0 -
Thank you!
I'm on 15.0.0... I'll upgrade and try again to see if there is any difference.
0 -
I have upgraded to version 15.1 and after adjusting lens correction for light falloff (I'll admit I was using a vintage, manual focus lens of about 50yrs old), which apprears to have a very similar effect as the vignetting tool, and making various exposure adjustments to even out the "lumpiness" of the shadows on the sky, looks much better... was also able to eliminate the halo around the tree.
I welcome comments and editing suggestions. (I am using this example to learn about the stitching tool... I realize not the best technique to take horizontal photos, but maybe a worthwhile exercise in learning the adjustments).
0 -
Hi Terence,
I would try a a higher setting for light falloff before stitching to see if it makes a difference.
Yes, vertical images are better for stitching horizontal panoramas, then you would have the outer parts of the lens on top and bottom rather than in the middle of the pano. And of course you have more sky and ground to choose from and/or a higher resolution as you can use a higher focal length.
Editing the stichted dng:
- Did you use the Clarity slider? I still see some halos and would lower the clarity
- Edit the sky with the Skin Tool Editor, pick in a nice area of the sky and try the uniformity sliders as well as others to see if it gets a little more uniform and more beautiful (unless your intention is to show pollution from the industry). Do this in an adjustment layer e.g. with a gradient if need be.
- Try to bring back some blown highlights with the HDR tool
Try another panorama stitching application to assess the quality of the C1 stichting.
0 -
Thanks for the comments but my problem is totally different. It has to do with the black parts which C1 use when the alignment between the images is not perfect.
I also opened a case but still did not get any answer!0 -
Just tested with 15.1 but no difference!
0 -
Im getting the same dark shadows in the sky, and halos around the darker parts (see around the tree in the foreground). I've tried the vignetting tool as a dirty way to adjust for light falloff on the individual images before stitching. Some results but it's a rough guessing game. This is done from 5 horizontal images.
-1
Post is closed for comments.
Comments
14 comments