I don't know, 40 years doesn't sound too old to me! The late seventies were, like, yesterday. Must agree with the sleep deprived pioneer though, as the Pentax 50's are nothing if not sharp. I don't own any K or M series lenses, but do have a truck load of screw mount Takumars including the 50mm 1.4 and 1.8. The 1.4 in particular is my favorite low light lens, even in the single coated Super Takumar, and the 1.8 is no slouch either. Agree with pioneer in that you may have a bad sample so don't give up on these lenses. Like FSU lenses you just keep buying them until you get a good one!