Hi icy, as I mentioned in your last thread, you need to use old m42 lenses in M mode with green button metering to get a proper exposure. The camera has no way of knowing what aperture you're using with these lenses, so it makes the best guess it can on exposure, but it is not accurate.
Originally posted by bobpur
Forget that Green button thing it just adds to your shutter count and makes you do 2 steps for each Pic !
What on Earth are you talking about? The shutter doesn't fire when metering with the green button. That's just bad info.