Extreme fisheyeWritten by Paul Bourke
A fisheye photograph is often associated with simply a wide angle shot, with a circular fisheye lens one first imagines a 180 degree field of view. There are real fisheye lenses that extend past 180 degrees, even as high as 280 degrees. Mathematically however a fisheye projection is not constrained by physics and optics. In the following various fisheye projections will be created using the equirectangular image below.
720 degree fisheye
1080 degree fisheye
720 degree fisheyelooking upwards
720 degree fisheye looking down