Is there any way to ...

[MikeFromMesa]

I was in Sedona, Arizona not long ago and took 4 separate photos which I stitched together into a panorama. From the image it appears that the vignetting at the edges of each photo have caused some darker blend spots in the stitched image. See the image at the link below:

https://www.dropbox.com/s/wp9dwnwetqax7 ... 2.jpg?dl=0

I can (and will) go back and try to remove the vignetting, but I suspect there will still be an issue. While I have reduced the size of this photo to make it easier to see the original image shows the transition locations clearly.

However, since the sky is clear, with no clouds, it seems like there ought to be a way to select just the sky and "average" out the blue in a way to decrease the transition points in the photo. I have tried several things, including blend modes, but have found nothing that really works. There are other things I can do like replacing the sky or placing overlays on it to try to reduce the sudden changes but I thought there was probably a standard way to do this sort of thing that I don't know and I was wondering if anyone here has any suggestions.

Thanks for any help.

[photoken]

I used the Hue Editor.

1. Use the Automask tool to successively add areas of sky to the selection until the entire sky is selected.
2. Add a Hue Editor adjustment layer as a child of the image. The HE adjustment will be automatically masked to your sky selection.
3. Use the eyedropper in the HE dialog, hold down the Ctrl key and click on the darkest sky value in one of the transition areas to set control points in the HE graph (on all channels).
4. Adjust the set control point in the HE dialog to even out the Hue, and the Brightness:
   sky hue.png
   sky brightness.png

You can see that I manually added another control point on the graphs so that the Hue and Brightness curves would be relatively steep around the control point set by the eyedropper.

[photoken]

BTW, if you're running Windows, a new version of the excellent Microsoft Image Composite Editor has just been released :
http://research.microsoft.com/en-us/um/ ... jects/ice/

It does automatic exposure blending, so it might be worth a try to see if it prevents the dark transitional areas you've noticed in your image.

[MikeFromMesa]

BTW, if you're running Windows, a new version of the excellent Microsoft Image Composite Editor has just been released :
http://research.microsoft.com/en-us/um/ ... jects/ice/

It does automatic exposure blending, so it might be worth a try to see if it prevents the dark transitional areas you've noticed in your image.

I use a Mac but I do have a Windows VM running on my machine so I can try it. That is the main problem with the Mac. Not the VM, but that there is so much really good software available for the PC.

I tested ICE a couple of years ago but found that it did a very bad job on some of my pano images. Very bad. And I returned to the software I used to use (Panorama Studio 2). I have usually been quite pleased with this software and it did try to merge the color variations into something much better than the image edges would have yielded, but just not good enough. I normally run my pano shots through something like Dxo Optics Pro to try to reduce the distortion and vignetting but that did not completely solve the problem this time. Too much variation in the sky across 4 images and, of course, the vignetting, which is clear in some single images.

I will give ICE another try. And I am going to try the Hue Editor as you suggested. Thanks.

UPDATE:

Worked really well. Modifying the hue helped, but in connection with adjusting the brightness the problem has all but disappeared, at least to my eyes. The more I use PL the better I like it. Here is the revised image:

https://www.dropbox.com/s/4khsndhn4k21e ... 3.jpg?dl=0

[photoken]

Worked really well. Modifying the hue helped, but in connection with adjusting the brightness the problem has all but disappeared, at least to my eyes. The more I use PL the better I like it. Here is the revised image:

Glad you've got it solved! Your image looks really good!

Regarding other panorama software: A long time ago I purchased Panorama Factory, and from what I remember it is a very good program. However, I rarely do panoramas so after I discovered ICE I uninstalled PF and haven't bothered to keep up with it for several years....

A thought about shooting images for panoramas:
If the main problem with getting an even sky is the vignetting in the original images, I would not use a wide angle lens (which sometimes has vignetting issues). Rather, I'd set my camera to 50mm (the equivalent in terms of 35mm cameras) and simply shoot the extra images as required. Since I would be stitching together multiple images anyway, there's no need to use a wide angle lens to reduce the number of images needed....

[MikeFromMesa]

A thought about shooting images for panoramas:
If the main problem with getting an even sky is the vignetting in the original images, I would not use a wide angle lens (which sometimes has vignetting issues). Rather, I'd set my camera to 50mm (the equivalent in terms of 35mm cameras) and simply shoot the extra images as required. Since I would be stitching together multiple images anyway, there's no need to use a wide angle lens to reduce the number of images needed....

That is probably very good advice. I normally shoot with a Canon 5D3 and its associated 24-105mm lens. That lens is very nice but has some severe distortion issues at 24mm and some vignetting.

I normally run the photos through Dxo's Optics Pro before trying to create a panorama and that pretty much addresses the distortion issues (LR would do the same), but there apparently is still some vignetting that has not been taken care of. The next time I do a pano, which I do fairly frequently, I will try at 50mm.

I do have a very nice, but low cost, sigma 12-24 that I sometimes use so I don't have to make panos, but I did not have it with me when I did these images. I was out walking around the Sedona trails and I just did not want to carry all of that heavy stuff. Just lazy, I suppose.

Thanks for the advice and I think the modified image was much more natural looking than all of those color distortions at the merge points.

[Lundberg02]

maybe I'm crazy but I like the original. The sky is too even in the edited.

[MikeFromMesa]

maybe I'm crazy but I like the original. The sky is too even in the edited.

Of course it is all a matter of taste. I liked all of the first image except for the section where the 3rd and 4th images were stitched (I shoot from right to left so that point is on top of the mountains toward the left of the image). There the edges just do not appear natural to me.

I am constantly surprised at how well the panos come out, even when I am stitching 4 or 5 or even 6 images together. With my old "bridge" camera it was easier because the electronic viewfinder provided support for panos helping to line up the stitching points. It is more "hit and miss" with a DSLR, but it still works out well enough, at least for me. That is, provided I am using good pano software.

[erikals]

PL
oops, wrong thread...