How to fit a vivitar lens?

One tip I have read is to remove the pin, that fouls the AF. You would probably have to take of the lens mount to get at it. Beware of small small springs and steel balls if you go this route.

Last night I resized the flange with a small saw.

First I unscrewed the flange to avoid any dust on the inside of the lens. Then it was easy going. (10 mins).

Second I checked for that famous pin to block my AF slot. Luckily it didn't had a pin.

I snapped the lens on my k10 - and it is now working - nicely.

Thanks all!

Glad to hear it , don't forget to post shot images taken with the lens