Originally posted by pacerr It's simple. Trade in your PK adapter for a PK/A.
There's no practicable or economical way to do a PK to a true PK/A adapter conversion as a one-off, DIY exercise.
H2
Originally posted by stevebrot Period...end of discussion! I own both adapters and the linkage for the PK/A is a non-trivial piece of engineering. If your camera is a recent Pentax dSLR, shoot with the PK in M mode and green button and be happy.
Steve
(...actually prefers his PK over the PK/A)
Actually, I am not so sure.
I think it all comes down to whether the adaptall II PK aperture lever motion is the same as the PKA lever motion.
If it is, then the modification, while not a true PKA mod, but a lens specific PKA mod is rather simple.
It is the same mod as any K to KA lens. What you need is, one spring loaded pin (the ones used in grid array IC mounts work, and are self contained, or one stolen from any PKA lens that is scrap) located correctly at the third pin location away from the lens locking pin (this may be tricky, i use a body mount from an old scrap cheap pka 2x TC as a drill template) , and then to correctly drill the insulating areas to match the minimum and maximum aperture for the lens in question.
This really only requires some patience and a little machine shop (drill press and soldering) skills.
I have not tried it as I only have one PK adapter and am keeping it intact (I have 2 PKA and 1 M42 adapter as well, but these reside on my 3 adaptall lenses)