On Sat, 26 Sep 1998 11:25:46 -0700, Roger Bergeron wrote:

>I walk away from camera shops confused when nikon AI vs NON-AI is
>explained to me. These shopkeepers must just write me off as retarded
>because they look at me like the difference is clear as day when they
>are done 'spieling'.
>I own an FM2n, (FM2 being a breed of camera that has been around so long
>that its lens mount has apparently made a transition of some kind).
>I've been guided by a rule " fear that prong thing " and " don't buy
>without actually attaching to the camera "
>Since some older lenses can be modified to fit my relatively new camera,
>I am probably missing out on some good deals in the world of used
>lenses.
>
> Can anyone offer a magic bullet that makes this situation Visually
>clear as day?

Yes - it's easy:
Feel the rearward-facing edge of the *aperture ring* on the lens.
If it's smooth all around, it's non-AI, and should not be mounted
on (AI) bodies with the small tab at the top-rightish edge of the
bayonette. If the aperture ring has two distinct rearward-facing
ridges, it is AI (Auto Indexing [for the meter...]), and can be
mounted on any Nikon SLR body, AI or non-AI. Ignor all else...;-)