In article <19970325024900.VAA17984@ladder01.news.aol.com>, exposedla@aol.com says...

>I'd like to know if anybody out there uses mirror lenses.I'm interested in
>buying one,either the nikon 500/f8 or the sigma 600/f8.Do you get fairly
>good images with these ???.My main use would be for bird/wildlife but if I
>get good results i'd use it for some of my outdor sporting events;the Long
>Beach Grand Prix will be in town soon and I'd like to get some shots with
>it.I'm aware of the drawbacks(fixed f/stop,not so easy to focus)but I'm
>willing to try them.

The best of the mirrors that I have tried is the older-version (non-macro)
Nikkor 500mm f8. And this is the only mirror I would dare use with a
teleconverter (it is quite good with the TC14/14B added [remove the
rear filter before installing the converter...], making a very compact
[but very slow], sharp 700mm lens). If you can keep the shutter speeds
high, and can shoot enough film (these ARE hard to focus, even on still subjects...) to increase your chances of getting sharp images, you can
get some good-quality images using the older (and usually very reasonably
priced) Nikkor 500mm mirror.
Hope This Helps