RB67 Back Frame Counter

Discussion in 'Medium Format Cameras and Accessories' started by tenny, Apr 29, 2010.

  1. tenny

    tenny Member

    Messages:
    2
    Joined:
    Apr 29, 2010
    Shooter:
    Medium Format
    My son is using an RB67 for college photo projects and has encountered a curious problem with his backs.

    Black and white film (Ilford) will correctly trigger the frame counter on the back, but color film (Fuji) will not. Once the first frame has been shot (he has to pull the darkslide while winding on to see film so that he can line it up, sacrificing the first frame), the film will advance and stop correctly, but no counter.

    This happens with both of his backs. I can only guess it has something to do with the thickness of the backing paper. Has anyone encountered this problem, or have a solution? If it is a mechanical problem, can anyone suggest a good repair resource in the Midwest (Chicago)?

    I haven't seen the camera myself, and I'm more of a Hassy user, no experience with Mamiyas.
     
  2. unclemack

    unclemack Member

    Messages:
    127
    Joined:
    Dec 23, 2009
    Shooter:
    4x5 Format
    One of the rollers has one (Pro-S) or two (Pro-SD) "rubber" friction rings. The upper ring, nearest the top of the insert, drives the frame counter/spacer. These rubber rings can become glazed - a thinner film base may be OK when a thicker- or stiffer-based film may fail to drive the roller.
    A small piece of rough cloth, slightly moistened, can be used to clean the surface of the "rubber" - this is usually all that's needed.
     
  3. tenny

    tenny Member

    Messages:
    2
    Joined:
    Apr 29, 2010
    Shooter:
    Medium Format
    Hmmm

    This sounds promising.

    Another member pointed out that there is unlikely to be much difference in the backing paper thickness, which makes sense: it has to fit on the spool.

    But the glazed ring could well react differently to the tooth of the paper.

    Anyway, some cleaning is obviously in order.

    Thanks