The term, fisheye, first mentioned in 1906 by a physician and inventor called Robert W. Wood based on the point of view of a fish inside the water. The practical use started in 1920 in the field of meteorology to study the formation of cloud which was called “whole-sky” lens. The angle from fisheye lens is commonly around 100 to 180 degree while the focal length depends of the film format or camera sensor being used.
The first fisheye lens for photographer produced widely in the early 1960. And commonly they were used because of their unique distortion view. For the 35mm format, the focal length is commonly around 8 to 10mm in circular fisheye and it is around 15 to 16mm for diagonal fisheye or full frame fisheye.
The kind of fisheye lens which was first developed was circular fisheye that can take a 180 degree angle and the result appears circular on the frame. That is why the corner or surrounding of the photo will appear black or dark.
After this kind of this circular fisheye lens, the one where the image fills the full frame diagonally is called full-frame fisheye or diagonal fisheye. The first lens of this kind which was produced widely was the 16 mm lens in 1970’s by Nikon. DSLR camera with crop sensor (Canon 60D for instance) needs a 10.5 mm lens to get the effect similar to a 16 mm lens on full-sensor camera.
Today, Sigma produces a 4.5 mm fisheye lens that can capture a 180 degree angle on camera with crop sensor. Sunex also produces a 5.6 mm fisheye lens that can capture a 185 degree angle on DSLR camera, 1.5x for Nikon and 1.6x for Canon.
Nikon produced a 6mm circular fisheye which was designed especially for an expedition to Antarctic. This lens has a 220 degree angle that can capture the whole sky and land surrounding it when the lens is pointed exactly right up there. This lens is no longer produced by Nikon and now it is used to create virtual-reality interactive images. Because of its super wide angle, the size is as big and as heavy as 5, 2 kg and the diameter is around 9, 3 inch.
An 8 mm fisheye lens produced by Nikon is proved to be beneficial in the world of science because of its proportional projection with zenith angle.