It is about 25 years since I did some hobby photography... Some of my knowledge is forgotten. Now I have bought a cheap APS film SLR camera (Canon IX7) and two m42 lenses (Helios 44, Industar 50-2), mounted on a EOS to m42 with metering capabilities.. The pictures turns out very sharp, but I have problem with consistent underexposed pictures. Is there a camera or m42 lens problem, or do I have to adjust ASA settings manually? Using the "sunny 16" rule gives proper pictures, but metering gives underexposure. Anyone?