I'm trying to get a bit more flexibility in my kit, and today my concern is cross-branding a macro setup.

I have a Nikon SB-21 ringflash with its AS-14 adapter for standard hotshoe usage. This works fine on my F-65, but the ringflash was originally issued with an AS-12 adapter for the weird F3 flash shoe. On the F3, since I don't have an AS-12, I use the AS-14 on an AS-7 adapter, and it feels like a Rube Goldberg design but works fine.

I also have a Pentax K2, which is as close to the Nikon F3 that Pentax ever came, and is a really superb machine. It has true TTL off the film plane, which I would like to put to use with the SB-21.

I realize that I can simply try it out and see, which I am doing, but I'm curious whether the combination can be worrisome for the electronic components of either unit, due to proprietary design incompatibilities.

Does anybody know?

Dan