Need help identifying a problem Mamiya RB67

Discussion in 'Medium Format' started by julien_denamur, May 6, 2016.

  1. Hi everyone,
    I bought a Mamiya RB67 on eBay, each part (back, body, lens and viewfinder) from different buyers.
    I got my photos developed and scanned in a professional studio, and this happened :
    ISO 100
    ISO 400
    A white streak ( to the right side on the B&W and left side on the color photos)
    I'm guessing the source of the problem is the back (Pro-S 6x7 120) during the exposure or when i load the next frame, other than that I have no idea!
    If anyone has an idea please heeeeelp me!
    I love film photography and my goal here is to replace the broken part to continue having fun with that beast!

    Julien D.
  2. Turn the RFH so that the wind lever is top right and the darkslide slot in on the right as you hold the camera to make an exposure. Open the RFH and remove the insert. Place each negative with the light leak over the film opening with the emulsion side facing the camera body and the image upside down.
    Now you know the section of the camera where the leak is. The top seal of the film insert is thin and shrinks with age, its likely the source of the leak. Check the camera back, the rotating adapter, and the film holder shell for proper mating and deteriorated seals.
  3. Thank you Charles for your indications.
    The rotating back seals seem to be in good condition but the all the seals in the insert are in the poorest condition.
    Your answer put me in the right direction and i managed to find forum threads from people having what seems to be the exact same leak.
    The answer that comes up most is that it might be coming from the door hinge area. However i went to a extremely dark room and used a flashlight to locate any light leak and there werent any, as I watched through the lens mount with the mirror up and no dark slide, the inside of the camera was pitch black.
    I'm very confused and considering replacing this back with a Pro SD.
  4. Light seals in the back can be replaced. It's a DIY project. There are miles of light seals in standard RB back. Here is a link to site selling sets of seals:
  5. paul ron

    paul ron NYC

    change the seals of the film back and rev back n then see if the problem is cured.
  6. Thank you guys!
    I ordered that new seals kit, I'll keep you posted!
  7. The RB67 I had had a flair type leak that checked to the wind lever area of the film holder. I removed the top cover, the seal looked good, but it leaked when assembled. I had to put a thin bead of black silicone runner on the top plate and under the seal to get it to quit leaking. No bright light in total darkness would have exposed the weakness either.
    Shoot a roll or ISO 400 film and process it after replacing the seals. Fast film shows leaks quickly.
  8. paul ron

    paul ron NYC

    charles, perhaps your leak was a lose screw in the plastic mask or the dark slide baffle
    bulging? ive never had such a leak requiring silicon to seal it.
  9. Paul,
    Put a RB in a hot closet or full sun most of the day window, leave it there for 10 to 15 years then come back and check its operation.
    The one I had was locked up and had a partially exposed roll of KodaColor in the RFH that was 10+ years out of date. The main cocking spring post was worn preventing the cocking gear from turning in the shutter. The body was good once I got the lens/shutter off and the cocking gears in the body reassembled.
    The top plate seal was over compressed and the plastic was possibly warped .0005 to .001 inch. The Pro SD was still available new then.
    +1 on replace the seals then test before shooting anything important.
  10. paul ron

    paul ron NYC

    hahahahahaha yeah that'll do it!

Share This Page