Zorki 3M Light Leak - Loose Winding Knob?

Discussion in 'Classic Manual Cameras' started by chuck_mathis, May 26, 2006.

  1. My Zorki 3M has a semi consistent light leak - consistent in that it affects
    every roll but inconsistent in that it doesn't affect every frame. The streaks
    run the full width of the film from edge to edge. I spent some time last night
    checking the shutter curtains (they're fine) and body of the camera (damn that
    thing is solid). The only potential issue I see is that the winding knob
    wobbles and appears to have a bit more gap than it should. Has anyone
    experienced this problem? Better yet has anyone fixed it? Any suggestions?
  2. I haven't encountered this in a Zorki. I had a FED that leaked light where the inner chassis bolts up to the shell in the front, with light getting through the vertical seam just in front of the film cassette... taping up that seam fixed it. I can't recall at the moment if the Zorki is quite the same, but I think the shell design is pretty similar. The other main place I'd look is the body/back seam at the right hand end below the advance knob, since the film is very close to this seam and unprotected. I haven't ever seen one leak down the wind knob shaft (yet)

    rick :)=
  3. My understanding is based on the Zorki 1, but here how I think it works. There should be a 'gasket' under the winding knob that prevents light from leaking under. If the knob is wobbly, the set screw may be loose, and if it has been like that for some time, the shaft where the knob mounts could be badly worn. I don't think that the worn shaft would let light in, but the missing gasket would. What it sounds to me is that the shutter is sticking and exposing the edge of the frame for a long period. This is common with this type of shutter.

    What happens when the shutter is tripped is that the first curtain moves across exposing the film. Then, the second curtain moves across blocking the light. There is a delay depending on the shutter speed of course, but in a nutshell, that what is going on inside. The problem occurs when the second curtain gets stuck on it's way across and leaves part of the film exposed. It will often hang, then release, sometimes quickly, sometimes slowly. You will need to remove the body and trip the shutter to see if there is smooth movement or not, but if you are not comfortable with doing this, you may want to have someone who is take a look at it for you.

    Often when this happens, some frames are overexposed on one side and some are blown completely out, either can certainly be intermittent problems. You can try sitting the unloaded camera in a sunny spot, with the lens cap on!, for a while until it gets warm and then trip the shutter repeatedly, moving up and down the speed scale. This may, may, loosed up the grease that causes the problem and allow a more reliable operation, but the bottom line is that you should have it cleaned by a repair person at some point if you want reliable operation, or take a shot at it yourself. Here are some links to give you an idea of what's involved.



    Hope that helps!

    - Randy
  4. One more thing. The www.rangefinderforum.com is a good resource for help with these cameras. They have a lot of members with them, and that do work on them so you might stop by there for help if you can't find what you need here.

    - Randy
  5. Fixed it! I loosened the set screw and removed the wind knob. There are two washers in
    the assembly - one flat and the other with a collar - but no gasket. I cleaned everything
    up, reassembled it and tightened the wind knob to the point I couldn't turn it then backed
    off just a touch. Once the set screw was tight I shot a test roll to confirm the leak is gone.

    The light leak was apparently due to the wind knob being loose on the shaft allowing the
    whole assembly to wobble.

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