Mamiya RB67 shutter Lag

Discussion in 'Medium Format' started by sina_khorsand, Mar 29, 2012.

  1. Hey guy,
    So I've been having problems with my RB67 Pro-S.
    Here's the deal: When the RB has the back on, most of the time when I release the shutter I hear the mirror slap, then sometimes it takes about a second or so for the shutter to actually release. The shutter releasing is not consistent, sometimes it takes up to two seconds, and sometimes it fires as it should. Here's the weird part- when I remove the 120 back, the shutter ALWAYS fires immediately with no lag, but with the back on, the firing is inconsistent. If I have the back on, and If I am using a shutter release, I activate the mirror to slap up, and there is delay. Only when the mirror is completely up then I am able to release the shutter with the shutter with the shutter release. So it seems that there is a mechanism in the revolving back that fully actuates the mirror, which then releases the shutter. I think the delay is maybe caused by a problem with the revolving back, and not the back itself (because this shutter delay happens with both of my backs), and is definitely not the lens because it happens with both my lenses.
    Does anyone have any clue to what the problem could be?
  2. The only connection I know of between the back and the shutter mechanism is the little pin that activates the double exposure protection. If this is not free to push through, the shutter wont fire--back is out of align. I suppose that if it is somehow stuck or sticky, it could delay your camera firing--I don't know where in the process the mirror moves up. Anyway, maybe watch when you release the shutter and see if the little red indicator appears in the film count window right away or just right before you hear the shutter fire.
    The other possibility is just that your firing mechanism is sticking--it rotates first to release the mirror and finally to release the shutter--maybe connected to the first issue.
  3. paul ron

    paul ron NYC

    So if the shutter releases normally without the back then any mehanical connection to the back is suspect.
    Have you fired the shutter off camera? Have you fired the body without a lens to see how the actuating ring is moving with and without the back?
    As already mentioned, are the pins in the rev back moving freely? Does this only happen in landscape or portrait mode or both?
  4. Thanks for the responses guys,
    So the pin mechanism on the revolving back that presses the double exposure prevention lock is missing. This shouldn't have an affect on the shutter lag. I think the problems is with the bigger pin on the body that presses the revolving back pin. I think it was bent, and I tried bending it back. So far, no shutter lag.
    Thanks for the help!
  5. I had this problem. I took the RB for a CLA and that fixed it.

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