In article <4sjj0e$20e@hobbes.cc.uga.edu>, mcovingt@ai.uga.edu says...
[...]
>I do my own slide duplication with an Olympus 80mm 1:1 macro lens,
>which performs very well. I've found that conventional macro lenses
>work OK if stopped down to f/11 or so, and conventional 50mm normal
>lenses are almost unusable.

Curvature of slides in the mount make duplication difficult, though the
Nikkor E and AIS (plastic mount) normal lenses work very well.

>Does anybody besides Olympus make a lens that is truly corrected for
>1:1 duplication? Surely Nikon and some others do. In my book, I need
>to give adequate coverage to product lines other than Olympus.

The 60mm f2.8 Nikkor macro is excellent at 1:1, though it may be
preferable to use a lens with some field curvature to try to
approximate the curvature of the slide....
Hope This Helps