Originally posted by surfar It works fine
I don't own a K-1, but that has not been my experience with the DA 50/1.8 on 35mm film. My shots show significant vignette (visible by direct examination of the negative) down to f/2.8. Edge and corner performance is also fairly poor and not to the same standard as my M and A series 50/1.7 lenses.
People who shoot the DA 50/1.8 on the K-1 and who are happy the results are just fine by me, but I personally would not recommend purchase of one for that purpose over other available options.
Steve
P.S. To balance my comments above, center sharpness is only a notch off the legacy M and A 50s at f/5.6 (not quite as good at wider apertures) and almost as good as the XR Rikenon 50/2 at the same.