Hi there, I have a SB600 and an Hasselblad 500 c/m. I would like to find the right exposure and I don't have a digital back, my tests will be visible after prints is there a way (not too expensive) to set the right intensity on my SB 600 (1/1, 1/4 ...) for the right Speed / aperture ? do I have to check tables or charts for that? thanks!!