I just received an adapter from Fotodiox to mount Pentax screwmount lenses on my G1. The adapter that came works okay with two of my lenses (55mm f1.8 and 135mm lenses), but it does not work with the one I bought it for. The Takamur 50mm F1.4 lens has a metal tab that extends below the threads into the chamber of the G1. It hits a lip on the Fotodiox adapter that prevents the lens from screwing in all the way. So, there's no way that it will work or focus to infinity. Presumably, this lens has the tab because the glass extends past the threads into the original Pentax SLR camera (the others do not do this). The tab is totally unnecessary with the G1 because the adapter adds considerable extra room between the lens and the inside of the G1. So, does anyone have any experience with this? Is there a different type of M42 adapter that does not have this problem, or am I stuck with no way to use this classic lens on my G1? Thanks in advance.