Scratches on film, Nikon F90x

[moleskin0r]

Hi,
I have a problem with scratches on my negatives. I use a Nikon F90x (or N90x), shoot mostly in black and white and develop it myself. I don't bulk-load film, I use normal 35mm-rolls.
Since I don't have enough time for a lot of printing in the darkroom, I usually scan my negatives first. I upgraded from an Canon 9000F II to a Opticfilm 8200, and that's where the problem became visible. Nearly every film I get out of my Nikon (also true for color-film when developed by the lab) has horizontal scratches on it, not on the emulsion side, on the "glossy" side. I realized that my old scanner was just a little less sharp than the new one, and the extra sharpness revealed the scratches. (Two scans of the same image attached for comparison, please ignore the dust on the second one).
(This question is not about the scanning! It's about the camera / scratches)
I even bought a second F90x on ebay and while the scratches were in general less intense, they are still there. Depending on which film I use it gets better or worse. My absolute favourite film is Adox Silvermax, and that's the one that also gets the most scratches (the picture with the plane is on Silvermax). I also use Kentmere 400, which works pretty well without much scratching. The film feels thinner than Silvermax (or Tri-X) which might be the reason. I also had scratches on Tri-X. I checked my dad's old color negatives from 15 years ago (shot with the same Nikon) and there were some scratches as well.
I do not have scratches on film that was shot with a X-700, and there were occasional scratches on film shot with a mju-ii.
I should have checked if they are also visible when printed in the darkroom, but I just don't have the time right now.
Searching the forum, I have seen some similar problems with Nikon cameras. What really puzzles me is that both the cameras are doing the same thing. Do motordriven cameras just tend to slightly scratch film? Is the scanner too sharp? (That really sounds stupid). Any advice? Any experiences?

Thank you so much in advance!
(I put some boxes in the pictures for clarification)

 

[darkosaric]

I have F801s (similar to F90), and never had this problem. Also no problem with F70, F60 or F55 that I had.
Scanner incluence you can test in a way that you rotate negative for 90 deg, and then scan the negative, and see where the line is.

 

[destroya]

do you develop your own film? Its a long shot, but i had a friend who did and when he cut his negs to fit in his storage sleeves, he used something to cut them which needed to film to be slipped in and then cut with a small guillotine style cutter. turns out his was scratching the negs as they were dragged thru, giving him straight lines along the negs. your look similar to his. just a thought

 

[moleskin0r]

Thank you for your answers. It‘s neither the cutting nor the scanner – the scratches are, with some light from the right angle, visible for the eyes even before cutting, as soon as the film is dry.

 

[blockend]

Scratches can be tricky to track down. Do they occur in the same place on each film? If so it's your camera pressure plate or a scratch on your scanner. Is it a one off event? Then it's dirt in the light trap of the film cassette. Is it on one strip of negatives but not others from the same film? The negative sleeve is the issue.

 

[MattKing]

Do the scratches cross the boundary between frames, or are they confined to the frames?
If they are on the non-emulsion side, check the pressure plate on the cameras.

 

[Sirius Glass]

Check the film transport, rollers and surfaces the film travels over, for dirt and corrosion.

 

[shutterfinger]

My F4 uses transport rollers in the back that hold the film flat, does the F90? I suspect the transport roller(s) are worn or not turning smoothly, bur on the pressure plate, or the back is slightly warped/bent so that it puts excessive pressure on the film.
A warp/bend in the back may not affect it closing correctly or cause it to have a slight bind on the hinge side or incorrect alignment on the latch side.

 

[ic-racer]

Just load a short roll and open the back after firing the shutter a few times. You can then see where the scratches start and stop. The scratches should be obvious on the opaque film.