| What some lens makers did was they made their lenses compatiable with both the Richoh A system, as well as the Pentax A system. If you take a FA lens (or a third party FA class lens), and take this Vivitar lens, line up the pins to each other, you'll see an extra pin that sits where the autofocus drive screw is on the FA lens. It's this pin that will cause problems, and thus, either needs to be filed down, or removed. |