Sorry to clog the board with such a silly question but I'm having trouble finding this small bit of information anywhere on google.
I have a hassy bay 50 cir-pol filter, I was wondering what exposure compensation I need to make for it.. 1 stop? 1 2/3?
I'm nowhere near any processing equipment for a couple of months so ICan't "shoot a roll and test"
It's going to vary, depending on amount of polarization (as you turn the filter). But 1.5 stops is the average light loss, when I tested mine using a spotmeter.
2 stops to be on the safe side, or round up to two if between settings. Hassleblad lens have advantage of 1/2 stop settings. (I'm making the assumption you are shooting negative film - if transparencies, err the other way)