zeiss m42 lens registration.

I have a zeiss jena 135, 3.5 that I mounted on a M42 to K mount

adapter and the lens focuses within 2-3 feet but not at infinity. Do I

have a registration or a lens problem? Has the same problem with

several Pentax cameras.

 

Thanks

Richard

I don't have any K to M42 adapters but I read over at spotmatic group that if you use some third party adapters you lose infinity focus since the M42 mount sits in front of K mount and not inside it as it should. M42 and K have the same flange depth so you should not lose infinity focus with a good adapter.

Would anyone have a recommendation for a good place to get an adapter?

 

Thanks Richard

I own a third party M42-K adaptor (made by HAMA in Germany) that I bought 15 years ago; it doesn't have any infinity focussing problems with Zeiss Jena (or any other) M42 lenses. Pentax OEM adaptors may still be available from the maker as they would fit the latest Pentax DSLRs as well. Novoflex will most certainly make one.

Mount the adaptor without the lens. If it fits flush, the adaptor is fine (K and M42 registers are the same), if it does not fit flush, you need a good adaptor like the Pentax one.

Mount the lens on a M42 body. I'll bet that it doesn't focus to infinty. Sounds like the lens needs adjustment.