Leica iii light leak

flx, or anyone here - I wonder if there has been any definitive identification of the source of these leaks that seem specific to the IIIg? After recent service, my IIIG is producing exactly the same leaks as flx illustrated here.

It seems clear it's light striking the rolled up film on the take up spool from somewhere near the area of the slow speed dial, but the flashlight test doesn't reveal anything for me. The vulcanite is quite damaged around that area and I'm thinking I might try some test exposures with the whole dial taped over securely to see if that eliminates it.

The person who worked on it will of course look at it again but in the event this is a problem peculiar to the IIIg, I thought I'd research a bit.

@qqphot What a timely matter, I received yesterday the scan from my test film post-repair.

To roll back in time, I wasn't capable either to spot the light leak even after hours of trying with my flashlight and my eye stuck inside the body. So I finally decided to let the pro work on it, anyway even if I had spotted the leak I would not have been capable to fix it properly myself.
So I brought my camera and the faulty negative to the most renowned shop in Paris on old Leicas. After inspection they recommended replacing all the "anti-voiles de cage" (in French), haven't been able to find the correct name in English, the body light blockers? All the small foam applied to block light.
Vulcanite had to be replaced with the work (mine was in bad condition) and they recommended to do a maintenance of arming plate, curtains, speed and translations which I accepted for a total of 576€ (ouch).

Here are the results.

Don't mind the color, I used a very old film that color shifted to run my test...

The default is not as strong as some other example but as it depends of how long you let the camera hanging in the sun while the film is in the exposed position, it's hard to reproduce.


Oh and half of the pictures look like that... So I guess I will have to pay a visit back to the shop and test their warranty on their work...



Actually can even find the light leak on messed up photo:



I need to go pickup the negative to have a better view on all of this.

This is very interesting. I decided today to conduct experiments on it.

First, I ran a roll of film through the camera with no lens, only a solid metal body cap, so no light could come in where the lens would normally be. This should produce completely unexposed film, but I found that the film still had exactly the same shape and pattern of light leaks on it as you have on your film.

Second, I exposed another roll of film taking actual pictures outdoors, but with opaque black tape covering the slow speed dial on the front of the camera and the area immediately around it. I used the camera normally and didn't cap the lens between exposures. This roll of film ended up completely free of all light leaks.

So I've concluded that at least in my case, for that very particular shape of light leak, the light is getting into the camera through the area surrounding the slow speed dial on the front, and striking film that is wound up on the takeup spool.

I've shipped my IIIg as well as the film back to the person who CLA'd it recently, and I'm sure he'll have more observations after taking it apart. But this seems pretty promising - if nothing else it means I should finally get around to removing the old damaged vulcanite and re-skinning the camera.

Thank you both for reporting back with your findings. Glad to see this actually may get resolved and one day I hope I can get the iiig back into daily action!

I think an easy test is to carefully cover the slow speed dial with an opaque covering like foil or black plastic and carry the camera around in the sun. I'm not sure if it relies entirely on the vulcanite surrounding the dial to be a snug fit, or if there is meant to be another layer of lightproofing beneath it or inside. The vulcanite on mine is quite damaged in that area which may explain it.

Well thank you everyone for the follow-up. I did confirm that my camera has a very very small leak from the self timer or slow speed dial. The leatherette is crumbling off around both of those.
I will look for a replacement skin and follow up later.