WHAT rS Al?

The Nikon FG-20 is an Al-type (Automatic Maximum Aperture Indexing) camera which performs full-aperture metering with Al-type lenses such as Al-S Nikkor, Al-Nikkor, and Series E lenses. All Al-S and Al-Nikkor lenses can be identified by a meter coupling ridge @ and a meter coupling shoe @ with two holes in it (see illustration). In addition, the Al-S or Al symbol appears on the f ront cover on the instruction manualfor each lens. Nikon Series E lenses also have the same features as Al-Nikkor and Al-S Nikkor lenses, except they do not have a meter coupling shoe.

Al-Type Lens