Nikkor 6mm f/2.8 fisheye lens is one of the most gorgeous looking lens – a lens that can actually see behind itself with the 220° angel of view!
Below is a sample photo taken with Nikkor 6mm f/2.8 lens on Nikon D4:
Below is a video of Nikkor fisheye lens 6mm f/2.8 with Nikon D4s: