dense, thin vertical lines in 35mm frame

[jaredangle]

Hey guys, I'm a darkroom lab assistant at my school's photography program, so in addition to setting up the darkroom and cleaning after sessions and mixing chemicals, I also help students troubleshoot problems with their film/prints/enlargers/cameras/etc.

Well, this week I've had a film problem that has stumped me. I've had two students have film turn out like the image below, but it's definitely not a camera or developer issue – the students are using different cameras, and all of their other rolls have been fine, except for these ones.

Any ideas? Could it be they're loading film onto a wet reel? We have stainless steel 35mm and 120 reels.

[sepiareverb]

Never seen that before. Both on TX? We had a bunch of strange circular spots on several rolls from one batch of TX about a year and a half ago. I mention it as it was of similar density.

[jaredangle]

Originally Posted by sepiareverb

Never seen that before. Both on TX? We had a bunch of strange circular spots on several rolls from one batch of TX about a year and a half ago. I mention it as it was of similar density.

I think the other student was also using Tri-X, it's the base film that pretty much everyone here starts out on, either that or T-Max. But everyone's using it, mostly locally bought at Penn Camera or online, and everyone's film is turning out fine except for these two. It's wierd...

[Pirate]

That line looks like it has a shape, like a counter top. If they knew each other I would suggest they were playing with their cameras and got a double exposure while finding out what buttons did what.

[jaredangle]

Originally Posted by Pirate

That line looks like it has a shape, like a counter top. If they knew each other I would suggest they were playing with their cameras and got a double exposure while finding out what buttons did what.

They're in different photo classes, I don't believe they know eachother.

[Photo_Smith]

You're talking about the stress marks running down from the sprockets? If so the most common cause is re winding in an anticlockwise direction.
I've seen this many times, and can replicate it. Here I folded the film back onto itself before development in order to show how pressure fogs film.



If you're talking about the thing someone else said is a table top, that is in the image and is part of the building roof support, it is behind the round structure as well. Just print the negative and you'll see.

[Dwig]

Originally Posted by jaredangle

... but it's definitely not a camera or developer issue – the students are using different cameras...

It is very likely a camera issue, though one of camera usage (read: misusage) rather than camera malfunction. It could also have happened after the cassette was removed from the camera.

I've seen this literally thousands of times. (I used to run camera stores that handled processing). What has happened is the film was rewound in the wrong direction. This folds the film around a sharp radius and the mechanical stress triggers an "exposure" that will then develop.

This reverse winding can happen during the normal rewind if they turn the crank the wrong direction. It can also happen if they twist the cassette's spool, turning it the way attempting to push the film out of the cassette. This can cause the film to fold over as it is reversed on the spool's hub. This twisting of the spool often happens when attempting to fish the leader out of the cassette for loading on a reel rather than following the best practice of opening the cassette with a bottle opener and sliding the spool out.