Help -- Lines/Scratches on Negatives

[ddf227272]

Hey all,

I'm new to these forums and couldn't find an exact answer for what I'm looking for. I'm shooting with a Bronica GS-1 and have noticed scratches on nearly every roll I've shot for some time now. I alternate between using 2 different 6x7 film backs and both film backs produce this issue, though the issue for one film back is clearly worse (more lines/scratches). I'm trying to identify the issue between perhaps the film back, camera, film, light leaks, how I'm advancing the film, etc. but could really use some additional thoughts. Have you ever experienced this issue before?

Here's a link to a Flickr album with some examples: https://flic.kr/s/aHsmRUKnQ6.

I get my film processed at Oscars in SF and don't feel like the issue is on their side. When I get my 35mm film processed at their lab there have never really been any issues.

I could really use some help. Thanks in advance for any thoughts/suggestions!

All the best,

Derrick

 

[shutterfinger]

Is the lab doing the scanning or are you?
Post a photo of the negatives not a picture made from them.
Lay the negatives on a light table, tablet opened to a blank text document, or hold in front of your monitor with a white background. Show the rebate area (edges) of the film. The last 3 pictures on your flickr appear to be a dirty scanner.

 

[TJPope]

I can say that my local lab did fine with 35mm, but then I had them develop MF they exposed the first and last frame to light somehow when developing it. So just because they do one well doesn't mean that will be the case for another format.

As for one back being worse, do you know for sure all the worse rolls were shot with the same back and it's not something you're just attributing to one back? If you know for sure, then it's likely not the lab and I unfortunately don't have any suggestions from experience with the camera. Thinking of my own MF backs, I'mm not sure what in the back could actually cause scratches like that as it would have to be something the film was rubbing up against. I imagine you've already done a visual / touch inspection looking for anything rough / pokey that could cause them?

 

[MattKing]

Welcome to Photrio.
If the scratches don't arise from the scanning (a real possibility) then they would appear to be on the back side of the substrate, not the emulsion side, because they are light in the positive image, rather than dark.
As 120 film has backing paper between the back of the substrate and the parts of the camera that make contact with the film, that would lead me to suspect the lab or the scanning.

 

[Sirius Glass]

You might want to check the film rollers, pressure plate and film path of the camera as well as photographs of the negatives.

 

[ddf227272]

Is the lab doing the scanning or are you?
Post a photo of the negatives not a picture made from them.
Lay the negatives on a light table, tablet opened to a blank text document, or hold in front of your monitor with a white background. Show the rebate area (edges) of the film. The last 3 pictures on your flickr appear to be a dirty scanner.

For sure! Please see photos attached. The scratches are definitely on the negative unfortunately. I do scan myself after getting the negatives back from the lab and thought it might be the scanner but don't have any issues with my 35mm negatives.

 

[shutterfinger]

Open the camera backs and check each roller the film travels over and the film gate pressure plate for any bur or unevenness with a sharp or protruding edge. A nylon stocking gently pulled over the rollers and pressure plate should slide smoothly.
Ask the lab for your backing paper back. Check it for any creases or lines. Try another lab.

 

[Dan Daniel]

Confusing. In your flickr image "007" the scratches start and stop with offsets and changing scratch positions. this makes me think that it is not happening in the camera. "010" shows the same thing. Is the lab putting the film in plastic, that stuff with the opening flap along one edge? Not sure what is involved in doing that... just thinking about what stage such scratches could happen.

You can use a cotton swab to rub down surfaces and look for snags if you don't have a nylon stocking around.

Visit Glass key Photo, take along your camera and backs and the negs, and see if they can help? They deal with a lot of medium format film gear. https://www.glasskeyphoto.com/#glass-key-photo

 

[ddf227272]

Thanks everyone for all of the ideas and suggestions. I ended up taking my camera over to Glass Key Photo and they really couldn't pinpoint the issue though they suspect it might be an issue with the camera's winding mechanism. The weirdest part of the issue is that the scratches only occur across the last few frames of the roll (which I should've shared earlier). While one of the film backs creates more scratches than the other, with both backs the scratches start around frame 7-9 (though it's not always super consistent with where it begins). Given the tension on the film is greater towards the end vs. the start, they suspected there might be an issue with how the film is being advanced in the camera. They called this a "longshot" though and didn't feel super confident in this cause.

They also looked at both of my film backs and the rollers felt both clean and smooth. If it were a film back issue, it's likely the issue would be present across the beginning of the roll vs. only at the end of the roll.

In terms of the film processing piece, my lab uses dip and dunk which makes me think it couldn't be an issue on their end. Also, they haven't had any other customers complain about any scratches on 120mm film.

Any more ideas or suggestions?