Guess that M light leak

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Brian Legge

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So last year I picked up an M2 here. It was meant as a backup and I only needed it in the winter at which time I had no issues with it. I finally shot it on an sunny 16 day and was dismayed to spot this light leak in several shots. Looking back at previous shots it looks like it was there but was so subtle that it wasn't noticeable at all. This is an M2 converted by DAG to use an M4 style tulip.

Does anyone have any guesses about the origin of the leak? Its always in the exact same place and looks like it has a hard line. The next really sunny day I'll try to isolate it a bit more. As it only shows up on the bottom I assume it isn't the curtains hanging. And it means its somewhere on the top side of the camera.

I figure I'll probably send it to DAG since he may be more familiar with his work on the conversion at some point but was curious if anyone here had any ideas first.

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Hi Brian
I had a very similar problem with an M3 a few years back. It turned out to be a bit of film stuck behind the pressure plate.
Cheers
Philip
 
Brian,
check the ribbon strip at the top edge behind the hinge on the back door. I've had an M6 ttl leak here. You can use decorators tape to seal the back door and do a few test shots. Make sure there is no debris between the hinge and the ribbon. Easy enough to take off the back door and clean,
regards john
 
Light from top and right side.
Leak from somewhere there.
My M6TTL lost a plastic bumper.
It leaked light that side but from side..
 
... something in the shutter blind possibly I've had tiny bits of film trapped in there and a cassette felt light trap on one occasion ... whatever it is, it's coming from the front of the camera not the rear because the gutter light trap's shadow can be seen at the bottom of the frame ... I'd try a rocket blower in the top shutter gutter first to see if there's anything in there
 
I had a similar light leak with m6 - turned out the curtain was coming off its way. Replaced the shutter and all is fine again. My light leak appeared on one or two frames per roll at first and ended with 4-6 leaks per roll.
Does every shot on your film have it?
 
Okay, I think we're on to something here. I had been trying to spot the leak either from the back or looking at the traps along the path of the curtains. I wasn't seeing anything there. I should have been looking at ways a leak could happen from the front a bit more.

It looks like light is leaking in from the rangefinder window. Holding a flashlight up to it, I can see a leak which I believe matches the symptoms.

While I don't mind working on some cameras, I'll probably check in with DAG on this one.

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philipus said:
Hi Brian
I had a very similar problem with an M3 a few years back. It turned out to be a bit of film stuck behind the pressure plate.
Cheers
Philip
Click to expand...

Hi Philip

I think my M2 has the same problem with your M3 now, it happens only when 1/500s or 1/1000s. As you can see on the film, something already came out from the picture frame. How did you fix that at last?

Cheers
Yang

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Brian Legge said:
Okay, I think we're on to something here. I had been trying to spot the leak either from the back or looking at the traps along the path of the curtains. I wasn't seeing anything there. I should have been looking at ways a leak could happen from the front a bit more.

It looks like light is leaking in from the rangefinder window. Holding a flashlight up to it, I can see a leak which I believe matches the symptoms.

While I don't mind working on some cameras, I'll probably check in with DAG on this one.

8552107780_ae18b1605f_z.jpg
Click to expand...

If this was the only light leak, how would it pass the curtain ? I think such a small leak located at front cannot be seen on the film during the opening time of the curtain. I think the leak comes from the back of the camera.
 
Good point. I was assuming that, given enough time with the curtain closed, light there was leaking around the curtain. Or that this leak was leaking in a places where it was. I don't have any proof this is the culprit but it at least is a place where light is getting in that I don't expect.
 
Wrap the back half of the body in a black cloth with gaffer and slpash strong light under the skirt made by that cloth with the front of the body pointing up.
Do this in a very low light area and look for light around and at rear of the film chamber with the shutter locked in B mode.
 
I'm having an identical intermittent leak on my M6 classic... What did this end up being? There's film in there right now so I can't check the rear door, but thats my gut...
 
Here's how to exactly locate a light leak (it requires 1 roll of film):

1. Load the camera in the dark, advance a few frames into the roll. Wind the shutter and leave it wound.

2. Go out into the sunshine with the camera. Without taking a photo, rotate the camera so that all sides get a good view of the sun (careful about the shutter curtains, though). Wander around a bit, make sure the whole camera gets a good soaking of sunshine.

3. Set the shutter and aperture and make ONE properly exposed image. DO NOT WIND THE FILM.

4. Go back into the dark, remove the film and develop it.

5. Place the film back into the film gate (I know, a little awkward with Leicas) with the emulsion facing the lens and the exposed negative upside down in the film gate in the camera.

== The leak marks on the film will be in the exact location of the leaks in the camera
== Leaks that extend beyond the negative frame into the margins are coming from the rear; leaks that stop at the edge of the frame are coming through/around the curtains.

It's a little tedious but it takes a lot less time than ruining a couple dozen rolls of film and then shipping the camera off for repair. The repairer will have to go through this process anyway to find the leak.
 
^^excellent advice, thank you. My leak extends beyond the frame. I'm now very confident it's the rear-door seals... Once I definitively locate it, what are my DIY options? The camera is otherwise in excellent condition and the last thing I want is to be without it for a few weeks... can I get or fashion a replacement strip for the top hinge of the rear door (my suspected culprit given the shape of the leak):

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UPDATE: it would appear that the very thin piece of fabric tape at the hinge is filthy...

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I cleaned it with some PEC-12 (which naturally lifted some of the glue... d'oh) and reglued it with a little contact cement. I'll try another roll of film and report back.

EDIT: the door had some play so I beefed up the bottom of the seal with thin strips of gaff-tape. Camera's sitting in the sun now.
 
I would contact Jon Goodman at jon_goodman@yahoo.com and see if he has a light seal kit for the Leica. He's put together some very good kits, and they're inexpensive.
 
It's not foam, per se (like on my nikons) it's a thin fabric tape. The door does have a very little bit of play, but the pivots seem good, and the play ended with my very thin gaff-tape addition. Somewhere on APUG there was reference to the tape on another M6... Can anyone confirm that it's supposed to be there?
 
I just took a look, mine has a very thin piece of fabric tape on the lower edge of the door (it would be under the baseplate in use). It almost but doesn't extend the full width of the door. This makes me believe that it's not for light sealing, but rather to stop any rattling noise.
No fabric tape anywhere else, but I have never taken the door off.
 
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