RB67 Back Frame Counter
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.
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.
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.