How long did you dry the film after you processed it? You should leave them to dry overnight otherwise the negatives can get scratched quite easily.
I normally let it dry overnight, but then sometimes I have developed it someplace else other than at home and I slip it very gently into (glassine?) sleeves.
I guess the scratches are in the direction of travel...
Does the camera back have some rollers that are in contact with the emulsion?
If so, make sure they're all rotating freely.
I thought of that too, but they do not seem to have any contact with the film at all. However I might reconsider using sliders for my backs more often as perhaps it might have come dust inside, which then finds itself stuck in between the film and a thin border of the back, and when I advance film - it scratches the film. That is my theory by now anyway.
There's dust which has come out white which means it must have been there during exposure (if it was on the film when scanned it would be black). So it looks like this is dust inside the camera and that might also be causing the scratches. I would be looking inside the camera for a solution.
Can you see the scratches on the film? Are they in the emulsion or on the back? That might also give some clues.
You mean the small black spots in these pictures a asume (not the white)? As the black spots shows that it was not exposed there... Well in fact when you mentioned this, I noticed in the bottom picture that the scratch on that picture has a black spot just above which is perfectly aligned with the scratch!
I indeed see the scratches very well on the film, I think they are in the emulsion, but I cant tell for sure.
