Light leak/ development issue or something else?

robonfilm · Nov 8, 2024

Hi, just developed this roll of FP4+ shoot on a Canon F1 CLA’d last week.

As you can see, a progressively thicker horizontal black line is present on the whole roll except for the last three or four frames.

I don’t see how a light leak in the camera could have caused it.

Could it be a developed issue? Any help is much appreciated

cmacd123 · Nov 8, 2024

could one of the Light seals have come louse? or a light baffle been re-sinalled out of place.

loccdor · Nov 8, 2024

I'd close the back, keep the shutter open in bulb mode, look through the shutter from the front while shining a flashlight around the back of the camera in a dark room.

Sirius Glass · Nov 8, 2024

Look to the ends of the camera, left and right. Either to door opening or the hinge are leaking light.

mshchem · Nov 8, 2024

Definitely looks like a light strike.

robonfilm · Nov 9, 2024

As a matter of fact the seals on the camera (especially the ones on the side) look fine. Could the leak have append off camera? Maybe in the Paterson tank before development?

Don_ih · Nov 9, 2024

Does that camera have a metal vertical travel shutter? Looks like a gap in the blades in the centre. The light is most intense across the image frame and bleeds out into the space between them. Take off the lens, open the back, turn off the lights, and shine a flashlight through the shutter to check.

robonfilm · Nov 9, 2024

Don_ih said:
Does that camera have a metal vertical travel shutter? Looks like a gap in the blades in the centre. The light is most intense across the image frame and bleeds out into the space between them. Take off the lens, open the back, turn off the lights, and shine a flashlight through the shutter to check.

Interesting, haven’t thought of that. However, the camera has a horizontal traveling shutter, so the curtains open vertically. Don’t see how it can cause an horizontal light strike.

rcphoto · Nov 9, 2024

Could this be caused by bending the film too much when loading onto the reel?

robonfilm · Nov 9, 2024

rcphoto said:
Could this be caused by bending the film too much when loading onto the reel?

I dont't recall bending the film that much. I did everything as usual, unfortunately.

Don_ih · Nov 9, 2024

robonfilm said:
Interesting, haven’t thought of that. However, the camera has a horizontal traveling shutter, so the curtains open vertically. Don’t see how it can cause an horizontal light strike.

Well, it generally can't. That leaves the hinge light seal or maybe a screw is letting in light in the take-up area (not sure there are screws in there - it's a guess. That doesn't look like any hinge light leak I've seen.

Saganich · Nov 9, 2024

That one frame that wasn't affected is interesting, a clue even, rules out the tank i think. Unless you get it in writing that seals were replaced as part of a CLA, they weren't.

MARTIE · Nov 9, 2024

I take it that this roll of fp4+ was not self rolled using a bulk film loader and reusable cassette?

Dave Ludwig · Nov 9, 2024

The streaking is inconsistent in width and always in the middle. Streaking is at the apex of the film curve and nowhere else. This suggests the film was semi stuck together in development and some frames broke free.

robonfilm · Nov 9, 2024

Don_ih said:
Well, it generally can't. That leaves the hinge light seal or maybe a screw is letting in light in the take-up area (not sure there are screws in there - it's a guess. That doesn't look like any hinge light leak I've seen.

I checked and I can’t see any screw in there. Just to be sure I just changed the foam seals near the hinge.

Saganich said:
That one frame that wasn't affected is interesting, a clue even, rules out the tank i think. Unless you get it in writing that seals were replaced as part of a CLA, they weren't.

Yeah, you’re right. I forgot to mention that the seals were not touched during the repair, as I had already changed them less than a year ago.

MARTIE said:
I take it that this roll of fp4+ was not self rolled using a bulk film loader and reusable cassette?

Yes, straight from the factory.

robonfilm · Nov 9, 2024

Dave Ludwig said:
The streaking is inconsistent in width and always in the middle. Streaking is at the apex of the film curve and nowhere else. This suggests the film was semi stuck together in development and some frames broke free.

Oh, okay. So you think the film was in contact when spooled in the tank’s reels?

Dave Ludwig · Nov 9, 2024

That is what I would suspect. If the film was warmer than usual when loading it may curl more than normal. I was looking at the edges for signs the film jumped the tracks but did not see any, usually there is a kink on the film edge, plus the result of that would be far more damage. You are getting an image underneath these areas and the film may have separated at some point but not enough for full development. Just what I suspect from similar situations.

robonfilm · Nov 10, 2024

Dave Ludwig said:
That is what I would suspect. If the film was warmer than usual when loading it may curl more than normal. I was looking at the edges for signs the film jumped the tracks but did not see any, usually there is a kink on the film edge, plus the result of that would be far more damage. You are getting an image underneath these areas and the film may have separated at some point but not enough for full development. Just what I suspect from similar situations.

I see. That’s very interesting, never thought the film could touch without jumping the rails. The good thing is that I can rule out the camera being the issue, the bad thing is that I don’t know how to avoid it in the future! Maybe pre-rinse could help?

koraks · Nov 10, 2024

Dave Ludwig said:
You are getting an image underneath these areas and the film may have separated at some point but not enough for full development.

I don't see how the film physically contacting itself on a reel would cause this excess density in the negatives. Film contacting itself results in either loss of density where developer couldn't access the emulsion, or entirely unprocessed areas of film where both developer and fixer couldn't get to it. The latter is more common, and generally is limited to small spots where e.g. reels contact the emulsion.

It definitely isn't pressure 'exposure' due to bending the film, either.

It looks like fogging to light. The blooming around the dense areas in frames 6A and 21A supports this. The question is just where/when that happened. My bet is on a camera-related issue because there appears to be a relation to the frame spacing (again, see frames 6A & 21A).

Don_ih · Nov 10, 2024

Generally, if film is touching itself in the tank, those areas end up undeveloped and unfixed, which looks different from the pictured film, which appears to have added density in those areas.

Have you checked the shutter for a hole? That's the last thing I can suggest.

koraks · Nov 10, 2024

Don_ih said:
Have you checked the shutter for a hole? That's the last thing I can suggest.

I would indeed expect that one or several holes in the shutter curtain would be the most plausible cause.

Don_ih · Nov 10, 2024

koraks said:
I would indeed expect that one or several holes in the shutter curtain would be the most plausible cause.

The only issue is, I had two fairly substantial holes in the shutter of a Leica IIIb and the resulting fogging wasn't nearly as bad.

The bright arc on the top right was from a slice burned in the shutter by the sun, probably from being on a shelf facing a window for who-knows-how-many-years. That could become a streak if I pointed the camera at the sun while advancing the film. That "can't" happen with an SLR, which has the mirror blocking the shutter.

koraks · Nov 10, 2024

Don_ih said:
That "can't" happen with an SLR

I don't quite agree; if there's a hole (or even a tear) in the shutter curtain, the hole will travel along with (preceding, or following) the slit that forms the intended exposure. Given a high shutter speed (narrow slit) and a large hole, the difference between the intended and the fogging exposure could result in dramatic overexposure. This may also explain why the problem shows up worse in some frames than in others. I would expect it's worse in a brightly lit scene that's photographed with a high shutter speed.

robonfilm · Nov 10, 2024

Don_ih said:
Have you checked the shutter for a hole?

koraks said:
I would indeed expect that one or several holes in the shutter curtain would be the most plausible cause.

The thing is that I used the camera a lot before the CLA without any issues, so the hole would have been caused by the technician. However (al least to the naked eye) the shutter seems to be fine. Hence why I tend to lean toward a light leak off-camera before the development

Don_ih · Nov 10, 2024

In my example, the cut in the shutter was almost 1/4" long. It didn't make any noticeable band of increased density from shutter operation. The light burn was from when the shutter was not moving. Even the slowest shutter speeds didn't have an impact.

To make a streak, the hole would need to be larger than the slit between the curtains (which is very narrow at high shutter speeds). So, maybe someone poked a pencil through his shutter.

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