Hello All, I have a good amount of gear for my (SLR) Bronica 6x7 and a 6x6 (TLR) Mamiya C330. I like switching between square and rectangular formats but was thinking of getting a 6x6 film back for my 6x7 because there are times when I want to use filters on the Mamiya but its just a little too tricky with a TLR, but I don't really want to invest in a whole new 6x6 system. I know you can shoot 6x7 and then crop to a square but I like to see a square when I'm "thinking" square, so cropping is a no-go. So my question is what are the advantages or disadvantages of getting a 6x6 back for a 6x7 camera. Thanks.