Pentax A 100mm f/2.8 macro. Everything about it is excellent. I used to have a Vivitar 90mm macro, I think it was an f/2.5. It was a most excellent lens, and went 1:1 with no adaptors.
I am also quite fond of the 100mm bellows lens. Interestingly, the helicoid extension tube makes the 100mm bellows into an easy to use short telephoto. William Robb
