I knew jpeg encoding was sometimes causing some trouble, but this is very strange:
the pictures hereunder are the same picture, out of camera, zero extra processing (other than resizing), the first one being the jpeg (standard settings, vivid colors), and the second one the embedded jpeg in the raw file (the "circles" are visible too, but much less visible).
This is the first time I see such a pixelization in one of my pictures (because of the discrete blue levels)
I didn't print yet, I see it on all my screens. Any comment ?
Shot with a Zeiss 50 1.4 ZF2 fully open on the D800
Did you say you see the circles LESS in the second one?
I see the circles much more in the second one.
This is called posterization. It's a result of the compression of the file, and is most easily seen - as you see it here - in very smooth gradients. Seems clear to me - though I've never tested - that the embedded JPG in that NEF is of lower quality than the highest quality settings in-camera.
This has been going on for many years. You see it especially in the clear blue sky gradiants. Just edit your raw file, and keep it at 16 bit. If you convert the raw to 8bit jpg, you will see the banding again.
Back in the days of 6mp digital files, I mostly converted from raw to jpg for processing. Since I shoot mostly landscapes, when I realized that 8bit files would show banding, and instead converting to 16 bit files didn't (unless pushed too much in processing) I stopped converting to jpg's and started converting to tiff files for processing. And I have been doing so ever since...
the embedded jpeg is only meant to be used as a reference picture, so it's very highly compressed... I would stick with the RAW file it's from, and process the image without too much further compression...
