HM...what about polarizing filters...I am using it in minolta slr, with ttl meter, and as I rotate the filter, I can see the effect and ttl metering takes care of exposure which also changes with rotation. The same 55mm polarizer fits on GSN perfectly, guess I can rotate it in front of my eye to see the correct angle, but how to determine the exposure? Can't think of nothing else but to bracket with asa dial by 1-2 stops and hope it will be OK... Any suggestions?
BTW, that goes for any, RF, but I have never used polarizers before, I just couldn't find any in 40,5mm for FSU lenses, not to mention the rollei mount..