I have a choice between the two Pentax lenses. The new ones is a FA 50mm f/2.8 Macro and the used one a mint M 50mm f/2.0. The price is about the same for each. I plan on using it with my K1000. Is there a big optical difference between the two? Convince me one way or the other. Once again, thanks for all the help!
Pat Wunsch