M42 adapters?

[matt_ruffino]

Im considering buying one to use with a Helios 44m so i can use it as a prime.

Do any of the adapters have any provisions for the little stop-down pin on the

back? Do any of them have problems focusing to infinity?

[j._bradley_deal]

It would help to know which camera you want to use it with. I have a Maxxum 70 that I use a 16mm Zenitar M42 with. Works well. You just have to make sure the lens lock is turned off. You will have to meter manually by stopping down the lens. I do not have infinity focus issues- that said a 16mm fisheye stopped 10 f11 or smaller is pretty much at infinity. I eventually got a Pentax Spotmatic body to use with the lens. Made it much easier.