F2AS not playing nice with Cosina lenses.

[Doddle]

I've had an F2AS and Cosina glass for a while, well today I tried to mate them.. and like the pandas at my local zoo, they weren't having it.

The AI groove on these lenses are too shallow, by maybe half a mm. If you stop down past f/4 the indexing tab shoots out and you're forced to hold the stop down button to get a meter reading.

The same lenses (40/2 Ultron, 50/1.4 & 85/1.4 Planar) work just fine on every other Nikon I own. Same goes for Nikon branded AI & AI-S lenses on my F2AS.

Just a little something I'd thought I'd share and I'm curious if anyone else ran into this - a google search gave me nothing.

 

[Larry Cloetta]

Good to know, thanks. Love my F2AS.

 

[Mark Wood]

I had a very similar problem with Tamron Adaptall lenses on an F2A and found the metering prism wasn't seated properly. A quick push on the top of the prism, it clicked into place and everything was fine again.

 

[splitimageview]

No problem here with my Zeiss ZF lenses and all my Nikon bodies (including an F2a.)

 

[stompyq]

Strange. My CV 40mm f2 works fine with my F2a

 

[CameraQuest]

I had a very similar problem with Tamron Adaptall lenses on an F2A and found the metering prism wasn't seated properly. A quick push on the top of the prism, it clicked into place and everything was fine again.

bingo.

that is probably the solution

 

[Mark Wood]

bingo.

that is probably the solution

Yes, the OP's description sounds exactly the same as the problem I had. The front of the prism was standing almost imperceptibly proud of the camera body itself but just enough to lose the ai connection when I rotated the aperture ring on the Tamron lenses. It still worked fine with Nikon lenses though and the meter was still connecting to the camera body too, so the cause of the problem wasn't immediately obvious.

 

[dtcls100]

Agree, improperly mounted prism. I have two F2AS bodies and they work perfectly well with my Cosina Voightlander Ultron 40 f2, as well as a host of Tamron SP Adaptall lenses.

 

[ColSebastianMoran]

Wow. THIS is helpful info. Thanks!