Ok this is the result after a simple test series of some stepuprings on a white cutting board.



And as we can see the scratch becomes clearly visible at f/5.6 and barley visible at F/4.0. Which tells us we can use the camera for portraets, but nothing else. So I need to find a solution for this problem.

The pictures are at aperatures of f/1.8, f/2.8, f/4.0, f/5.6 and I used a sb-600 on ttl settings for this pictures.