I have modded two OM lenses, and two other similar C/Y lenses, to PK use. Simple, easy, cheap. The problem is that the bayonet flags on an OM or C/Y lens base are just a little too thick to fit under the PK mount lugs. So, I tapered those flags so they DO slide in. Here's what I wrote about my first conversion, a Vivitar 35/2.8:
I used a Dremel cutting blade that had already been worn down from cutting other metal parts. I used its edge and side to taper the tops of the leading edges of the lens' bayonet blades.
Definitions: By 'top' I mean the surface that's AWAY from the camera; and by "leading edge" I mean the part that first engages with the blades on a PK mount. By 'taper' I mean I changed that leading edge from blunt to wedge-shaped.
The blades on this lens are about 1mm thick. With the cutting tool, I reduced the thickness at each leading edge to about 0.5mm, and tapered it back about 8mm. I have no OM body (yet) to test this on, but it looks as though it should still fit firmly onto an OM body. But I also removed the mount-grip gear and the aperture flags (in the way on a PK mount) so if this ever sees an OM again it'll be totally manual and unsecured.
With that mod, the OM lens can be force-fit onto a PK mount. If you want more security, use the dremel blade to cut a slot (1mm wide and deep, 5mm long) into the lens base for the PK locking pin to slide into. That will secure the lens on the body.
Originally posted by lguckert79 
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