...it's typical for a reflex viewfinder to show 'less' than is recorded on film. In 35mm format, I think only Nikon claimed 100 percent coverage for their F, F2 and F3. Anyone have experience of how much 'less' the TLR viewfinder shows?
6.4 Finders Coverage Measurements of the screen apertures on a C330 and C220 give a value of 51mm (to the nearest millimetre), while the image area is 56mm. 51/56 gives a finder coverage of 91%. This is partly to allow for the fractional variations in the positioning of the lenses when they are changed.
The 'famous' Mamiya TLR site has it all! Thanks for remembering. I guessed the TLR viewfinder has a rather large 'safety' margin - 91% is quite low. I took a photo recently at close distance using the 55mm
and the paramender, except i forgot to 'crank-up' after framing. The framing was still OK though.