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