In article <4oapub$180i@uni.library.ucla.edu>, birdy@ucla.edu says...

>I own the Nikon 8 mm F2.8 and 16 mm F2.8 fish-eye lenses. I enjoy
>using them. I have found them useful in my work (engineering) and also
>fun for other types of photography.
>I've seen references to the older Nikon "mirror-up" fish-eyes. There was
>an 8mm F8 (the original), a 6 mm F5.6 (220 deg), a 10 mm OP F5.6 and a
>7.5 mm F5.6. I have seen the 8/F8 and the 7.5/F5.6 at camera shows and
>other stores. I have been looking for a 10 and 6 for quite some time.
>I've seen a 10 advertized twice, but they were both sold before I learned
>of their existance.
>Does any know about these two lenses. Of course I would like to purchase
>one, but just discuss them with a current owner would be more success
>than I've had.
>I know about Nikon's 6 mm F2.8, but unless I'm suddenly made King of
>England, I will never own it!

Ah, another fisheye fanatic....! (Too bad I can't get my clients to
understand their advantages, alas!) BTW, if you want to see how good a superwide can be, try a Nikkor 16mm f3.5. I am not enthusiastic about the
10mm fisheye, since the projection is orthographic (very moderate barrel
[and coverage] over most of the circular image area, with the remains of
the 180 degree coverage smushed into the highly curved edge of coverage),
though I would like to see a longer focal-length version (with the highly
curved part excluded from the 35mm frame) - though a 16mm on a 1.4X is a
good substitute. The 6mm f5.6 is quite good, and a wonderful image maker.
You can shoot from a high place straight down, showing the whole world
below plus a band of sky around it - or from the ground up, showing
everything in one photo, including the surface the camera is
resting on. I would like to try a 6mm f2.8 on a 2X
converter one of these days.......
Hope This Helps