For historical reference, here is a photo of a Nikkor 6mm fisheye sitting in Ford Oxaal s office:Message 1 of 5 , Nov 18, 2011View SourceFor historical reference, here is a photo of a Nikkor 6mm fisheye sitting in Ford Oxaal's office:
Note the nice black case for the lens.
I had a chance to try his 6mm on my 5D at the time.
Impression: poor at f2.8, best at F8-f11. Works with 5D via EOS adapter. Way too expensive to borrow. Funky lens cap.
Tiny 24mm image circle for such a huge optic.
Here's a photo of Ford holding the Nikkor 6mm: