Nikon 8mm f2.8 AIS Fisheye-Nikkor
The Nikon 8mm f2.8 AIS Fisheye-Nikkor is probably the lens you picture when someone mentions a fisheye... unless you're an ichthyologist. But assuming you're not, this is probably the lens. With a huge, bulging front element and a built-in filter turret, this lens is clearly not meant for day to day shooting: it produces a circular image in the middle of the frame, without any attempt to correct distortion. Field of view is 180 degrees, so watch where you put your feet. This lens is in really excellent cosmetic condition, with only the most minor wear; focusing is smooth and diaphragm is clean. There are a few very minor marks on the front element which will not affect imaging; there is some light hazing around the edge of one central element which is unlikely to materially affect images (we haven't seen any effects.) Image quality is excellent. This is an unusual lens, and you might not need it, but perhaps you want it anyway?