I have a chance to buy some 220 film at a reasonable price and an RZ67 22 insert at a very reasonable price. My RZ67 backs are all 120 backs - but I am not clear whether the outer shell is actually the same for 120 inserts and 220 inserts.
So ... can I use a 220 insert with my existing 120 shell or do I need to buy a 220 back ?
The 120 and 220 inserts are interchangeable in the shell, ie. they use the same shell. However, the shells for the different RZ67 models are different and not interchangeable, as explained in the chart at: http://www.reznitsky.info/Mamiya/Comchart.htm. In other words the insert has to match the shell, which has to match the body.
> In other words the insert has to match the shell, which has to match the body.
The Pro and Pro II film backs work on both RZ bodies (Pro and Pro II). The inserts do have to match the shell so a Pro II 220 insert needs a Pro II shell. 220 backs are super cheap now that basically no one makes 220 film anymore. I'd just get a whole 220 back and go from there.