Originally posted by MESuperian I’ve ordered is an autofocus Tamron PK/AR mount
I hope that's a typo, it's a manual focus lens. I'm puzzled, The images show a Vivitar, the info below is for that.
Originally posted by MESuperian Does this have a Ricoh pin?
Yes it does and it's the nasty pointy one which is more likely to cause problems. See pic.
Originally posted by MESuperian If so how do I modify it?
Stand the lens on its end with the mount up.
Remove the four screws and lift the mount up carefully
(the other brass pin is lightly spring loaded, don't lose the pin or spring). Both pins are captive.
Remove the 'Ricoh' pin
(sorry I've forgotten how but it's easy). Bend up the tab, remove the pin, bend the tab back.
Re-assemble (note, the red dots on the body and mount must line up) then black out the '/R' of the PK-A/R to show it's been converted.