Help with filters, please.
Going through the filters that came down to my with my Dad's Contax IIIa, I find a UV filter, a Y2, an R1, a blue one marked FLASH, a brownish one marked "daylight A" and an orange one marked YA3. My questions are these: How much more exposure do I allow for the R1? What does the YA3 do and how much extra exposure? And just out of curiosity; What do the "daylight A" and the "FLASH" ones do? I'd only use the ones for black and white.
Leica M3, Contax IIIa, Rollei MX, Nikon F, FM, Minolta Maxxum, Pentax K1000.