this nikkor 20mm f2.8D lens has been design before 1989 for 35mm film format but it will work on both - FX (and will see 94 degrees) and DX formats as well. On DX you will get only 71 degrees view because sensor is smaller.
Nikon - Nikkor 16mm f/2.8D AF Fisheye Lens for Nikon DSLR Cameras
Nikon - AF DX Fisheye-Nikkor 10.5mm f/2.8G ED Wide-Angle Lens - Black
(9)