RB67 back on 2x3 Graflock

I have read you can use a RB67 back on a camera with a 2x3 graflock

back. I have a few questions? Can this be done? Is the film plane of

the RB back at the proper location in respect to the ground glass

focus surface? I am using a Horseman 980 are any modifications

required to the camera or back? Will any RB back work? Thanks.

Hello Scott.

 

The Mamiya RB and the Horseman both uses a 2"x3" Graflock-back, so the film-plane position of a RB-67 film holder is the same as the ground-glass position of the Horseman. Likevice, You ought to be able to use the Horseman's 6x7 cm roll-film- holder on a RB-67 camera. Also Graflex made roll-film holders for 2"x3" Graflok-backs (only the film-holders with lever-type film advance can be recommended, the ones with "nob-type" film-advance is reported to be haunted by film-flatness-problems). Due to the sheer body-size of the RB-film-holders not all RB-67 film-backs can be used on the Horseman. Personally I found that the 70mm Mamiya RB-film-holder was to wide (due to the big film-chamber for the 70mm cassettes) to be able to mount on my Horseman 970. I advice You to try with the RB-film holder in question befor buying it.

 

Good luck!

I remember reading about using RB backs on Graflock-backed Mamiya Press cameras (only a small percentage of Presses have Graflok backs, but they do exist), specifically to gain access to a 70mm back. The issue I remember is that the only backs you can use without modification are the early ones without interlocks. Later Pro-S and Pro-SD backs have interlocks that a non-RB camera has no way to release. If you REALLY need to use one of these backs I can't imagine disabling the interlocks would be too big a problem for a competent repairman. My understanding is that most, if not all, of the pre-RB Graflok rollfilm backs have serious flatness problems.

Thanks for your responses. I purchased the RB67 back. It requires some modifications to the back of the camera. The covers on the graflock have to be removed and the spring clips have to be clearanced slightly. The handle on dark slide also has to be removed.

The interlock for the dark slide works perfectly. This probally would not be worth doing for most people.