Somewhere during the Pro-S years Mamiya introduced a way of shooting 6×8 on the RB67. Several different components are needed to shoot 6×8 and in the end you will end of with a 5.6cmx7.5cm (compared with the 5.6cm by 6.8cm negative for the normal 6×7 back). However, the 6×8 frame size will only be used when the back is rotated to portrait.
From my notes on RB67 6×8; To have a full 6×8 setup, first start with a Pro-S or Pro-SD body (the Pro body can be used with some work), then add the following.
- a 6×8 power back.
- a 6×8 light baffle–which lies between the revolving adapter and the body. You can tell what sort of baffle you have by taking off the current revolving adapter. There is a flat black baffle held in by four screws, if this says “8” or “6×8” you are ready to go.
- Pro-SD 6×8 revolving adapter
- a 6×8 Matte screen to get full 6×8 view(optional)
If all the pieces are assembled, you should have a 5.6cm x 7.5cm frame size. APUG user jtcliff was able to test different configurations of the above components and the resulting frame size.
- RB67 Pro Body + RB67 Pro revolving adapter + 6×8 power back: 5.6cm x 7.2cm negative.
- RB67 Pro Body + RB67 Pro-SD revolving adapter + 6×8 power back: 5.6cm x 7.3cm negative
- RB67 Pro Body + RB67 Pro-SD revolving adapter+ 6×8 power back + “8” light baffle: 5.6cm x 7.5cm negative
In the end, you have to wonder if all the work is really worth it for an extra .7cm…