Light leak or dev. error?

M-88 · Feb 3, 2019

Hello

I'ev encountered unpleasant surprise after developing my most recent roll of film. Here are the two segments where it all occured:

It looks like a light leak from behind the camera and the most logical action would be to test two rolls of film, one with the camera back accurately taped and other without doing so, to see if it occurs again. But I can also see sprocket hole marks (outlined with red in images) so I thought maybe it's due to film wrongly inserted on the developing spool, or some other reason related with developing? Even though it went on the spool pretty easily.

Film area between frames 19 and 24 is the only place where it happened. Nowhere else.

Any thoughts?

Thank you!

M.

P.S. FP4+ is such a good film. Is there counterpart for it in Kodak film assortment?

Murray Kelly · Feb 3, 2019

Didn't go thru an x-ray machine on your holiday?

M-88 · Feb 3, 2019

Murray Kelly said:
Didn't go thru an x-ray machine on your holiday?

No, I haven't left the country for four years already. I buy Ilford stock locally, the shop has the full selection from that brand and even Delta 3200 came out excellent a few months ago. HP5+ from the same shipment as this FP4+ came out good as well.

Ian C · Feb 3, 2019

It’s useful to know what camera was used. If the camera has a horizontal-travel ribbon shutter, it might be a shutter problem. The crisply-defined vertical bands are consistent with that type shutter curtain with intermittent hesitation in travel. The light bands suggest an intermittently sticking closing curtain allowing excess exposure before resuming travel. If the camera has a vertical-travel multi-blade shutter, such as a Copal SQ, then this explanation makes no sense.

I’d expect the light-leak explanation to produce the problem in a greater number of areas over the length of the film and to be consistently positioned in the same place on each frame affected. The bands don’t resemble what I’ve seen when the film has been loaded incorrectly on a reel, touching adjacent loops of film, and spoiling development where film-to-film touching occurs.

Note that frames 19A, 21A, and 24A have a band in the same place, but the band on 20A occurs at the left side of the frame. Frames 22A and 23A show no obvious banding.

scheimfluger_77 · Feb 3, 2019

Since the light leaks occur intermittently in the sprocket holes, I’d say it is a problem with the pressure plate in the door. Does the door latch securely? Does the pressure plate function properly? Good luck.

M-88 · Feb 3, 2019

Ian C said:
It’s useful to know what camera was used. If the camera has a horizontal-travel ribbon shutter, it might be a shutter problem. The crisply-defined vertical bands are consistent with that type shutter curtain with intermittent hesitation in travel. The light bands suggest an intermittently sticking closing curtain allowing excess exposure before resuming travel. If the camera has a vertical-travel multi-blade shutter, such as a Copal SQ, then this explanation makes no sense.

My apologies, I should have mentioned it in the original post. The camera is Ricoh XR7 with vertically traveling shutter blades. Here's a photo:

Ian C said:
I’d expect the light-leak explanation to produce the problem in a greater number of areas over the length of the film and to be consistently positioned in the same place on each frame affected. The bands don’t resemble what I’ve seen when the film has been loaded incorrectly on a reel, touching adjacent loops of film, and spoiling development where film-to-film touching occurs.

So if it's not the horizontal shutter, which it isn't and if it's not the film touching itself, we have a mistery.

scheimfluger_77 said:
Since the light leaks occur intermittently in the sprocket holes, I’d say it is a problem with the pressure plate in the door. Does the door latch securely? Does the pressure plate function properly? Good luck.

Yes, everything is in good shape, this XR7 was visually and mechanically perfect when I bought it. The film door closes properly and pressure plate sits firmly (tested from the lens side of the camera on Bulb mode).

Peltigera · Feb 3, 2019

Ian C said:
It’s useful to know what camera was used. If the camera has a horizontal-travel ribbon shutter, it might be a shutter problem. The crisply-defined vertical bands are consistent with that type shutter curtain with intermittent hesitation in travel.

But not if the banding extends beyond the image frame.

My guess is the seal by the back hinge. The band is in a slightly different place in each image and varies in intensity. As the film winds onto the take-up spool, the diameter of the spool increases and the position of each frame on the spool will change slightly. The variation in intensity will be dependant on the time between shots. With a very slight light leak and fairly fast shooting, the film will only be on the outside of the take-up spool for a brief time. With slower shooting, the film will be on the outside of the take-up spool for longer and so the light leak will be more pronounced.

M-88 · Feb 3, 2019

Ian C said:
Note that frames 19A, 21A, and 24A have a band in the same place, but the band on 20A occurs at the left side of the frame. Frames 22A and 23A show no obvious banding.

Might it be due to a light leak from the film door hinge? Where the film is "spooled" during the winding process? It was a sunny day, while every other shot was made in overcast weather.

Peltigera said:
But not if the banding extends beyond the image frame.

My guess is the seal by the back hinge. The band is in a slightly different place in each image and varies in intensity. As the film winds onto the take-up spool, the diameter of the spool increases and the position of each frame on the spool will change slightly. The variation in intensity will be dependant on the time between shots. With a very slight light leak and fairly fast shooting, the film will only be on the outside of the take-up spool for a brief time. With slower shooting, the film will be on the outside of the take-up spool for longer and so the light leak will be more pronounced.

This makes sense and I was thinking just the same. Maybe I should sacrifice one roll and expose suspected area to flashlight or any other strong light source on certain frames to see if it occurs.

Peltigera · Feb 3, 2019

Frame 21A shows an image of a sprocket hole next to an actual sprocket hole. This confirms that the light leak occurred where the film was both out of the cassette and wound over itself. So the light leak is impinging on the film while on the take-up spool. Must the the back hinge.

M-88 · Feb 3, 2019

Peltigera said:
Frame 21A shows an image of a sprocket hole next to an actual sprocket hole. This confirms that the light leak occurred where the film was both out of the cassette and wound over itself. So the light leak is impinging on the film while on the take-up spool. Must the the back hinge.

So basically nobody thinks that it's a developing error, which means I'm "okay" at doing it? This is wonderful!

Peltigera · Feb 3, 2019

Certainly not a developing error!

Ian C · Feb 3, 2019

A careful examination of the light seal at the film-door hinge should give you an idea of its condition. Replacing the seal is a simple job if needed.

Here is the material to use (urethane foam). It cuts to size with scissors, X-Acto knife, or single edge razor.

I find that it helps to use a razor to pry a bit of the backing material from the adhesive side. Then you can grasp the backing sheet and peel it from the foam. If you try to do so with your fingers without starting the separation with a razor, the urethane won’t separate from the backer without tearing.

https://www.bhphotovideo.com/c/prod...y_tool_jht9541_15_camera_light_seal_form.html

M-88 · Feb 3, 2019

Ian C said:
A careful examination of the light seal at the film-door hinge should give you an idea of its condition. Replacing the seal is a simple job if needed.

Here is the material to use (urethane foam). It cuts to size with scissors, X-Acto knife, or single edge razor.

I find that it helps to use a razor to pry a bit of the backing material from the adhesive side. Then you can grasp the backing sheet and peel it from the foam. If you try to do so with your fingers without starting the separation with a razor, the urethane won’t separate from the backer without tearing.

https://www.bhphotovideo.com/c/prod...y_tool_jht9541_15_camera_light_seal_form.html

Thank you, I've done it once for a friend and once for me, I should have some leftover foam somewhere

Truzi · Feb 3, 2019

I've a Sears KS-2, which is a rebranded Ricoh XR-7, and have had the same problem. It looks like a leak at the hinge as others have stated.

I didn't notice the problem on my camera until I took some pictures without the half-case; which blocked the light from entering that area.
When taking several photos in quick succession, the film on the take-up spool would have several unaffected frames, as they were wound-on and covered before enough light could fog them, so you may not have the problem on each frame (also mentioned by others).

I used some thick felt as a light barrier. I intend to do a foam replacement at some point.

M-88 · Feb 3, 2019

Truzi said:
I've a Sears KS-2, which is a rebranded Ricoh XR-7, and have had the same problem. It looks like a leak at the hinge as others have stated.

I didn't notice the problem on my camera until I took some pictures without the half-case; which blocked the light from entering that area.
When taking several photos in quick succession, the film on the take-up spool would have several unaffected frames, as they were wound-on and covered before enough light could fog them, so you may not have the problem on each frame (also mentioned by others).

I used some thick felt as a light barrier. I intend to do a foam replacement at some point.

Unfortunately I haven't had a case for XR7. Although many people hate never-ready cases, I consider them to be mandatory for a "complete" rig, even have a fancy leather case for my OM-2. I'll glue the foam for the next session. Thanks everyone!

foc · Feb 3, 2019

When checking the door light seals, you should also check the seal on the film type inspection window in the door. I have seen this cause problems in cameras before.

M-88 · Feb 3, 2019

foc said:
When checking the door light seals, you should also check the seal on the film type inspection window in the door. I have seen this cause problems in cameras before.

No such thing on XR7 though. My F80 has it, buth thankfully it's still intact.

Light leak or dev. error?

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