22 Replies Latest reply on May 12, 2015 6:06 AM by trshaner

    [LR6/CC] Clipping threshold changed?

    Samoreen Level 2

      Hi,

       

      I have a number of photos for which I'm absolutely sure that no clipping was signaled in the histogram in LR5. These are photos that were selected for an exposition and I always check this point. The clipping warnings are always on in my LR. Now, when loading these pictures in LR6/CC, many of them indicate a clipping either in the blacks or in the whites. Given the number of affected photos, I'm not considering a mistake.

       

      So either the demosaicing process has changed (but Adobe told us that nothing was changed in this area), or the clipping threshold used in the histogram has been modified. Since I didn't change any setting for these pictures, I don't see any other explanation.

       

      Anyone having noticed the same phenomenon?

       

      Thanks in advance.

        • 1. Re: [LR6/CC] Clipping threshold changed?
          Samoreen Level 2

          Hi,

           

          New tests (other system, LR5/LR 6 comparison) have confirmed that the clipping threshold has actually changed. Or there's a bug in LR6.

          • 2. Re: [LR6/CC] Clipping threshold changed?
            Ian Lyons MVP & Adobe Community Professional

            FYI, the only time the clipping display is accurate is when image is displayed at 100%. I think this is a point often overlooked by users and trainers alike.

             

            Also, there have been feature enhancements (some minor some less so) in Develop module that could affect the 'Clipping' threshold in image. The most likely being GPU acceleration. I suggest you try switching it off and on whilst viewing one of the affected images. On my system (Mac) I can flip between some clipping and no clipping when image is viewed at standard screen size. When I zoom to 1:1 the amount of clipping changes to very little and lots of clipping. Again, on my Mac system, there is less clipping shown when GPU is On.

             

            Edit

             

            Corrected typo errors

            • 3. Re: [LR6/CC] Clipping threshold changed?
              Samoreen Level 2

              Ian Lyons wrote:

               

              FYI, the only time the clipping display is accurate is when image is displayed at 100%. I think this is a point often overlooked by users and trainers alike.

              OK. But if one looks at the same image, on the same display, on the same machine with the same zooming factor in both LR5 and LR6 and if the clipping warning is different, this necessarily means that the threshold has changed or that there's a bug  or that the computation has changed (which can be the case due to the use of the GPU - however, without or without GPU we have observed the same phenomenon).

               

              Now, this deserves a warning from Adobe. If an image is assumed to have no clipping in LR5 and if the same shows clipping in LR6 while nothing has been changed, this can be disturbing.

               

              I'll do additional tests based on what you said. Thanks.

              • 4. Re: [LR6/CC] Clipping threshold changed?
                trshaner Adobe Community Professional & MVP

                On my Windows 7 System with LR CC I see no difference in clipping levels with GPU enabled and disabled. I checked a Canon 5D MKII raw image in LR 5.7.1 and LR CC with default Develop settings the same in both.

                 

                Histogram Highlight Clipping Indicator

                Exposure LR 5.7.1  LR CC 2015

                Red            .88          .93

                Yellow        .93           .98

                White         .98         1.03

                 

                I'm seeing a .05 EV difference between LR 5.7.1 and LR CC 2015, which is very small. Samoreen how much of an Exposure difference are you seeing?

                 

                There is a known issue with LR 6/CC Soft Proof, which I have reported. It's a different issue, but just wanted to make you aware of it. It affects the RGB reading displayed in the Soft Proof Histogram, but not the clipping indicators.

                 

                Lightroom CC Soft Proof Histogram Displays Incorrect RGB Values

                • 5. Re: [LR6/CC] Clipping threshold changed?
                  Samoreen Level 2

                  Thanks for the details.

                  trshaner wrote:

                   

                  I'm seeing a .05 EV difference between LR 5.7.1 and LR CC 2015, which is very small. Samoreen how much of an Exposure difference are you seeing?

                   

                  Sometimes not much, like you, sometimes more, sometimes the behavior is absolutely inconsistent. I have an image where I created a white border by using post-crop vignetting. The histogram tells me something like 58, 56, 76 for the RGB values in the border areas. If I activate the clipping warning, the whole border is shown as clipped. The same image displayed in LR5 didn't show any clipping.

                  • 6. Re: [LR6/CC] Clipping threshold changed?
                    trshaner Adobe Community Professional & MVP

                    I'm not seeing any difference in Post Crop Vignette between LR 5.7.1 and LR CC. I suspect your LR 6 default Develop settings may be different than your LR 5.7.1 defaults.

                     

                    Test the image with the Post Crop Vignette by Exporting to DNG using LR5.7.1. Check the DNG in LR5.7.1 for clipping indicator level and RGB values for the Vignette in the extreme corner. Open LR 6 and Synchronize the folder. Check the DNG file for the same values in LR 6 by changing only the Exposure slider. Since LR6 uses the Develop settings saved to the DNG in LR5.7.1 the values should be the same in LR 6.

                    • 7. Re: [LR6/CC] Clipping threshold changed?
                      Samoreen Level 2

                      trshaner wrote:

                       

                      I'm not seeing any difference in Post Crop Vignette between LR 5.7.1 and LR CC. I suspect your LR 6 default Develop settings may be different than your LR 5.7.1 defaults.

                       

                      Migrating to a new major version never changed default settings until now. Am I correct? LR5 is no longer on my system anyway. But as I  mentioned above "New tests (other system, LR5/LR 6 comparison) have confirmed that the clipping threshold has actually changed. Or there's a bug in LR6.". The test has been made by another user near me.

                      • 8. Re: [LR6/CC] Clipping threshold changed?
                        trshaner Adobe Community Professional & MVP

                        Agreed, but the best way to verify the problem is to create a DNG in LR 5, measure the clipping values and then open it in LR 6/CC and measure the values again. If you can post a raw file that exhibits the issue to Dropbox or other download site I'll be glad to run the test on my Windows 7 LR5.7.1 and LR CC 2015. I'm not seeing the issue with my Canon 5D MKII CR2 raw files. What  camera files and OS are you using?

                        • 9. Re: [LR6/CC] Clipping threshold changed?
                          Samoreen Level 2

                          trshaner wrote:

                           

                          Agreed, but the best way to verify the problem is to create a DNG in LR 5...

                          Thanks.

                           

                          Since I'm considering re-installing LR5 and my old catalog, I'll try to find enough time to do this myself. Thanks again.

                          • 10. Re: [LR6/CC] Clipping threshold changed?
                            trshaner Adobe Community Professional & MVP

                            I just had a chance to go back and check some more CR2 files in LR5.7.1 and compare clipping in LR CC 2015. The 2nd one I tried (portrait orientation image) shows a highlight clipping indicator difference of +.19 EV. What's interesting is that you're seeing lower clipping levels in LR CC.  For all images I've measured so far the Exposure clipping level is higher in LR CC. I created a DNG test file in LR5.7.1 and it measures the same +.19 EV difference in highlight clipping level as the CR2 raw file. Clearly there is a bug in LR 6/CC that is causing the difference and it's the same with 'Use Graphics Processor' enabled or disabled on my Windows 7 system.

                             

                            If you hold down the SHIFT key when moving the Exposure slider you can change the setting in 0.01 EV increments. What's interesting is that some images have identical highlight clipping indicator levels in LR5.7.1 and LR CC (i.e. no issue). What is the largest difference you are seeing?

                            • 11. Re: [LR6/CC] Clipping threshold changed?
                              Samoreen Level 2

                              Thanks for testing.

                               

                              trshaner wrote:

                               

                              What is the largest difference you are seeing?

                               

                              I can't say exactly since I have not yet re-installed LR5. But it seems to depend widely on the image itself.

                               

                              Adobe told us that the processing didn't change in LR6 but I'm starting to doubt. Maybe no change in the algorithms but a possible bug introduced in the coding.

                              • 12. Re: [LR6/CC] Clipping threshold changed?
                                trshaner Adobe Community Professional & MVP

                                Samoreen wrote:

                                Adobe told us that the processing didn't change in LR6 but I'm starting to doubt. Maybe no change in the algorithms but a possible bug introduced in the coding.

                                That appears to be the case, but I'd like to determine why only certain image files are different in LR 6/CC. If we can nail that down I'll submit a bug report.

                                • 13. Re: [LR6/CC] Clipping threshold changed?
                                  Samoreen Level 2

                                  Hi trshaner

                                  trshaner

                                  That appears to be the case, but I'd like to determine why only certain image files are different in LR 6/CC. If we can nail that down I'll submit a bug report.

                                   

                                  Now that we have seen both negative and positive shifts in the clipping threshold, we can assume that the problem is not related to a change in the threshold value itself unless they are now computing a variable threshold depending on the image contents.  Hey! Could it be something like that ? In that case, the difference should be more visible when handling high key or low key images. I'll have a look in my library...

                                  • 14. Re: [LR6/CC] Clipping threshold changed?
                                    Samoreen Level 2

                                    Samoreen wrote:

                                     

                                    In that case, the difference should be more visible when handling high key or low key images. I'll have a look in my library...

                                     

                                    I have something for you to test. This link points to a high key image using post-crop vignetting (Canon CR2 + XMP file).  In LR6, they are areas where the RGB value is about (90%, 90%, 90%) or even less and that are marked as clipped which was not the case in LR5 (again I can't test with LR5 now).

                                    • 15. Re: [LR6/CC] Clipping threshold changed?
                                      ssprengel Adobe Community Professional & MVP

                                      I reported this to Adobe.  It happens in both LR6 and ACR9.

                                      • 16. Re: [LR6/CC] Clipping threshold changed?
                                        Samoreen Level 2

                                        ssprengel wrote:

                                         

                                        It happens in both LR6 and ACR9.

                                         

                                        Yes. I just noticed this when opening the same files in PS via ACR.

                                        • 17. Re: [LR6/CC] Clipping threshold changed?
                                          trshaner Adobe Community Professional & MVP

                                          Samoreen, what version of LR5.x are you using? I'm seeing very similar highlight clipping readings using LR5.7 and LRCC 2015 with the posted CR2 and XMP settings file.

                                          • 18. Re: [LR6/CC] Clipping threshold changed?
                                            Samoreen Level 2

                                            trshaner wrote:

                                             

                                            Samoreen, what version of LR5.x were you using?

                                            5.7.1. As noticed by ssprengel, the same problem is present in ACR 9.

                                            • 19. Re: [LR6/CC] Clipping threshold changed?
                                              trshaner Adobe Community Professional & MVP

                                              ssprengel wrote:

                                               

                                              I reported this to Adobe.  It happens in both LR6 and ACR9.

                                              Thanks Steve.

                                              • 20. Re: [LR6/CC] Clipping threshold changed?
                                                ssprengel Adobe Community Professional & MVP

                                                I'm seeing the same issue in PS-CS5/ACR 6.7 rendering PV2012 so it's not new.  I turned off the grain to make sure that wasn't affecting how high and low the values were.

                                                • 21. Re: [LR6/CC] Clipping threshold changed?
                                                  trshaner Adobe Community Professional & MVP

                                                  I was afraid that might be the case, which is why I asked what LR5 version Samoreen is using. I always thought the clipping threshold triggered when any channel reached 100% and the color of the clipped channel(s) appears in the Histogram clipping indicator. It's now triggering at lower levels in both LR5 and LR6 with certain images.

                                                   

                                                  With Develop defaults, Highlights = -100, and the below Post Crop Vignetting settings Highlight clipping is showing at only 76% in both LR5.7.1 and LR CC 2015.


                                                  Dentelles_047.CR2

                                                  Post Crop Vignette Highlight Clipping.jpg

                                                  • 22. Re: [LR6/CC] Clipping threshold changed?
                                                    trshaner Adobe Community Professional & MVP

                                                    This is interesting. I Exported the Dentelles_047.CR2 to 16 bit ProPhoto RGB TIFF using the same settings as in the above screenshot. The red area shown as 76% in the CR2 image file shows as 100% in the TIFF Export file, so the red clipping indication in the screen preview image is correct. It's only the RGB readings in the Histogram that are incorrect! LR CC 2015 and LR5.7.1 both exhibit this behavior.

                                                     

                                                    This is very similar to tthe LR 6/CC Soft Proof issue I reported, but LR5 doesn't exhibit this issue:

                                                    Lightroom CC Soft Proof Histogram Displays Incorrect RGB Values

                                                     

                                                     

                                                    Dentelles_047-CR2_76 percent vignette level.tif

                                                    Post Crop Vignette Highlight Clipping_TIFF Export.jpg