How to use old vollapsible 50 Elmar

[akiralx]

Just got an old 50 Elmar f/2.8 for my M3 (and maybe M8) but I'm unsure how to mount/use it.

At the moment I can't move the focus ring off infinity. Should I be mounting/unmounting it at any aperture setting? When extended I can rotate it a quarter turn but there's no click to imply it's fixed for use.

Thanks for any help.

 

[payasam]

Probably infinity catch, Alex. If there's a tab sticking out at the base of the focussing barrel, it will have a spring-loaded button that you must press before you can take the lens away from infinity.

 

[akiralx]

Yes! That's it.

Many thanks.