Originally posted by Lowell Goudge This goes back to the *istD, Av mode and M mode meter differently for M42 lenses. I think it has to do with the fact that most M42 lenses have black , I.e. insulating bases, in M Mose the camera is programmed to interpret this different ly than Av mode
Yup, seems that way. The Helios seems to be the only one of my M42 lenses with enough bare metal to get accurate metering in Av mode. Will have to fix the Sicor-XL and ZM-5SA so I won't have to fiddle with foil, would you recommend filing off some paint with sandpaper? Or maybe I'll just get a some aluminium duct tape and do a less permanent fix? XD
I still think it's silly, why would the lack of electric contact make it underexpose by almost exactly 2 EV stops in Av mode but not in M mode? The amount of light that comes in through the lens is still the same. Doesn't make any sense to me. (I don't really expect anyone outside of Pentax to know the answer to that, it's more of a rhetorical question)