3 Replies Latest reply on Feb 19, 2011 6:21 AM by Vit Novak

    Banding in ACR workflow

    Vit Novak Level 3

      Playing further with profiles for Nikon D7000, I finally noticed that there is indeed some strange kind of banding, that was mentioned by several users for different cameras. It is most noticable on saturated violet colors, as shown by this example (in Adobe RGB)

       

      First picture is part of my test chart, developped by NX2, and second picture is the same test chart, developped by ACR6.3 using D7000 Camera Standard profile. If you compare those two pictures, you can see appearance of vertikal dark lines. It's more evident on the third picture, which shows the difference between first and second, multiplied by 10.

       

      D7000_Banding1.jpg

        • 1. Re: Banding in ACR workflow
          Vit Novak Level 3

          Some further analysis shown me that problem is in value of green color, as shown here. These graphs show value of R, G and B color on violet color in test charts, from black to saturation level. First graph is made on picture from NX2. Second one is made on picture from ACR using D7000 Camera standard. As you can see, green color doesn't rise smoothly in the shadows and that's the reason for banding. Even NX2 introduces some banding, but it's much more intensive on ACR

           

          D7000_Banding2.png

           

          I made my own profile for D7000 with double number of value segments and result is shown on third graph. Banding is somewhat reduced, but it still exist and is still visible on the photo, so I'm not very satisfied with this solution. To reduce banding to the level of NX2, profiles would be much bigger than they are now (several MB).

           

          Unfortunately, I didn't find a better way to reduce this problem than just enlarging the profile. Error is caused by interpolation method of lookup table of the profile in ACR internal workflow and amplified by applying tone curve and gamma curve further in ACR workflow, so only a change of interpolation algorithm can solve this. Although this problem won't be visible on 99% of pictures, this error is quite big and I hope that this problem will be addressed in the future

          • 2. Re: Banding in ACR workflow
            MadManChan2000 Adobe Employee

            Thanks for the report, Vit. Would you mind sending me (or otherwise posting) the NEF? I have an idea on how to address this, and would like to include your image in the test set.

            • 3. Re: Banding in ACR workflow
              Vit Novak Level 3

              Hi, Eric, I sent the nef to your mail at yahoo.com

               

              Vit