Originally posted by Stratman Speaking of the green button. I just recd my K10D about 3 1/2 weeks ago, and have found metering M lenses very hit and miss using the green button in manual mode. At f4-f5.6 it seems to do well, below f4 it seems to underexpose, and above f5.6 it seems to overexpose. the higher the f stop, the more pronounced the overexposure. Is this common with the K10D? I also have a K110D and use the AE-L button to do the same thing with M lenses, and it seems to be much better at metering with the old glass.
It's not hit and miss but quite systematic.
with very fast lenses (F1.4 50mm K moount for example),. it under exposes wide open, gets exposure right by F2.8 and then tends towards over exposure up to F11 where it starts going back a little.
Starts at -1 stop at F1.4 and +1.5 stops at F11, to +.75 at F22.
Other lenses all do similar behavor but each one is a little different.
I mapped all mine out by taking a sequence of shots of a block wall in even sunlight, and then measuring the grey scale.
With contrast set neutral on jpeg conversion each 45 is 1 stop between the range 25 and 230 approximately.
By comparison my *istD is so consistent across the entire apature range that if it was an EKG the paitent would be dead. Not even a ripple.
Fortunately, I use my manual lenses most on the *istD and automatic lenses on the K10D.