7 Replies Latest reply on Jul 25, 2013 7:33 AM by MartinF13

    Camera Raw synchronizes highlights and shadows not exactly

    MartinF13

      I use Camera Raw 8.1 to prepare various NEF-files for stitching to a panorama. It will become multirowpanoramas. Some of these files have a 80 percent of very light sky and some have 0 percent of sky. All files have been exposed manually and equally. Then I open all NEF-Files for one panorama together in Camera raw and select them all.

      When I use shadows slider (= Tiefen in German) the effect on the files varies. In the files with much sky the dark earth is lightend considerabely. In the files with no sky the earth is lightened only very moderately.  Using highlights-slider (= Hoehen in German) I get a similar problem.

      This becomes a big problem, when I stitch these files together!

      Why does that happen, and how can I avoid this problem?

        • 1. Re: Camera Raw synchronizes highlights and shadows not exactly
          ssprengel Adobe Community Professional & MVP

          Adobe raw processing of highlights is non-linear so even if you didn’t adjust things, there might be problems, and as you’re seeing, the new PV2012 adjustments for shadows and highlights, and clarity among others are relative to the specific image range of values so things won’t match if you are using any of those.

           

          You could try making an HDR stitch without adjusting anything in ACR beforehand, and do your toning the adjustments afterwards, perhaps with Photomatix or by hand in PS.

           

          You could try other stitching software that tries harder to match and blend things even when the exposures aren't the same.  I use AutoPanoGiga and can use different exposures for different areas of the scene and it usually blends things properly.

           

          AutoPanoGiga, and the less expensive Pro version, have a 30-day trial version that watermarks the image but it would be enough to see if it works better:

          http://www.kolor.com/

          • 2. Re: Camera Raw synchronizes highlights and shadows not exactly
            MartinF13 Level 1

            Thank you ssprengel !

            I use Autopano Giga since years and that makes the problem much less dramatic as it could be.

            I would like to know if there are any linear adjustments in RAW-Converters. And I prefere to adjust my files first in a RAW-Converter, because of the loss-free and reversible adjustments.

            I have read everywhere that I can adjust RAW-files simultanuously to get corresponding results. But for multirow-panoramas that is not absolutely right.

            In the future I will avoid extreme differences in a raw-developed series of files. And then I hope that autopano giga will eliminate  slighter differences.

            And I hope for a RAW-Converter with liner adjustment-slides.

            • 3. Re: Camera Raw synchronizes highlights and shadows not exactly
              ssprengel Adobe Community Professional & MVP

              If you use ACR to convert to 16-bit TIFs without adjusting the highlights and shadows, and merely adjust the exposure a little to make sure the shadows highlights aren’t clipped, then you shouldn’t be losing any information when you stitch, and afterwards you can adjust the either the LDR (low-dynamic-range) or HDR output of the panorama software using ACR (I think) and work with the shadows and highlights after the stitch has been performed. 

               

              Of course, if you are working on 360-degree panoramas then you’ll need to use Photomatix or similar which has a special 360-degree mode for toning adjustments that wraps the adjustments around the edges to keep things seamless when viewed with the edges joined.

               

              The camera-manufacturer may have raw-conversion software that works more consistently for you. 

               

              I have used AutoPanoGiga to stitch multi-row panoramas with sky in them and it seems to blend things well.  You may want to experiment with the color-matching transfer function and try both Gamma and then Brightness matching (or whatever the parameters are) to see if one is superior.  I think I use Gamma most of the time and rarely see the transitions even though I use dissimilar exposure settings for each subpicture.

              • 4. Re: Camera Raw synchronizes highlights and shadows not exactly
                MartinF13 Level 1

                The problem is not when I do slight adjustments in ACR but only when I do considerable adjustments. As you propose I save the developed NEF-files as 16-bit Tifs. Then I use Autopano pro to create LDR-Panos. I'm not interested in 360° Panos. If you want to see, what kind of panos I create look here: http://www.martinfranz-muenster.de/index-e.htmhttp:// You can imagine that I have to make sometimes considerable adjustments in ACR before stitching. I am a bit old-fashioned therefore I still avoid HDR-processing.

                 

                But I found out something very interesting this morning playing around with ACR: When I use the gradient curve (2nd window, in German: Gradationskurven) instead of the first window with an aperture as icon (in German: Grundeinstellungen):

                 

                Modifying these curve in a series of pictures with and without sky (as described above) results in linear adjustments or at least much more liner adjustments! That is what I was looking for!

                 

                So I will modify my workflow slightly: I do the first strong adjustments in ACR with the "gradient curve" and minor alterations in a second step with "basic settings" (Grundeinstellungen).

                 


                 

                Message was edited by: MartinF13

                • 5. Re: Camera Raw synchronizes highlights and shadows not exactly
                  Vit Novak Level 3

                  I'm not sure it will do the trick - problem is that PV2012 has automatic highlight recovery that depends on amount of highlights. It can cause different brightness of neighbor photos for panoramas. I'm not sure you can undo it completely with curves or other sliders (this behaviour was already discussed here in some other threads, not connected with panoramas)

                   

                  PV2003 and 2010 don't have this 'feature', so you may try them as alternative

                  • 6. Re: Camera Raw synchronizes highlights and shadows not exactly
                    ssprengel Adobe Community Professional & MVP

                    So APG will finesse over the slight discontinuities in brightness such as with small toning adjustments or automatic highlight reduction in PV2012, but when you want to do large adjustments, the curve tab works better. 

                     

                    What I’m still not understanding from your workflow is why can’t you adjust the LDR panorama in ACR afterwards?  Also, I wasn’t suggesting you are doing HDR panoramas, just that the intermediate format of an HDR format out of your panorama software might give you more dynamic range to work with if you doing the adjustments after stitching and the original pictures are almost clipping.

                     

                    Your panoramas do look nice.

                    • 7. Re: Camera Raw synchronizes highlights and shadows not exactly
                      MartinF13 Level 1

                      Ssprengel you have made some interesting proposals:

                       

                      I tried immediately to adjust one of my new panorams with ACR after stitching. However I think I'll stick to my traditional workflow: After stiching I process the PSD-file with PS CS6. There I keep all the adjustments in seperate adjustment layers which I save in the PSD-file. So I can modify them later during printing process if necessary. I feel that this is better reproducible than ACR adjustment.

                       

                      I never thought of using HDR format as an intermediate format during stitching. I will try this soon. But anyhow I have to open the NEF-files (do some white-balance) and save them as tiff-files, because stitching from NEF-files is possible but not reccomended. The next step is stitching to a file in HDR format. This file will become very large, considering that my PSD-files are approximately 1 GB large. I'm sceptical whether this workflow will do better than my traditional one.

                       

                      This morning I stitched 10 panoramas (from my yesterday shooting) with my modificated workflow: In the first step I use ACR to adjust (lossfree) white balance,  black- and white-point, (a rough approximitation to) overall brightness and lights and shadows , lens-vignetting. I used  "gradient curves" and thereafter "basic settings" before saving the tiff-files. I think this is a minor but important improvement. Stitching and PS-adjustments was done as usual.