----- Original Message ----- From: "J. C. O'Connell" Subject: RE: 50 or 100 mm
> FREE is psuedo-zoom. It is pretty obvious if the focal length > varies and it does. Pentax has made both dedicated and pseudo- > zoom macros. I believe the switch occurred when they went from > F4 designs to F2.8 designs in the early 80's. Of course any lens > that "does" Macro is a "real" Macro lens but when I was referring to the > "classic" macro lens designs I meant the fixed focal length designs > optimized for a specific closeup magnification, similar to the > designs of modern high end enlarging lenses. > Not withstanding, the macro lenses with the fixed rear element design are incredibly good lenses. I recall reading in the literature of the day when I bought the A100mm f/2.8 macro that the design allowed for superior lens performance throughout the focal range. As the lens is excruciatingly sharp from 1:1 right through to infinity (no small feat), there is absolutely nothing wrong with the lens design. William Robb
