Wiktionary
alt. (context photography English) A wide-angle lens having an extremely wide field of view (approaching or exceeding 180 degrees) and producing images that are circular or distorted by curvature at the edges. n. (context photography English) A wide-angle lens having an extremely wide field of view (approaching or exceeding 180 degrees) and producing images that are circular or distorted by curvature at the edges.
WordNet
n. a camera lens having a wider than normal angle of view (and usually a short focal length); produces an image that is foreshortened in the center and increasingly distorted in the periphery [syn: wide-angle lens]
Wikipedia
A fisheye lens is an ultra wide-angle lens that produces strong visual distortion intended to create a wide panoramic or hemispherical image. Fisheye lenses achieve extremely wide angles of view by forgoing producing images with straight lines of perspective ( rectilinear images), opting instead for a special mapping (for example: equisolid angle), which gives images a characteristic convex non-rectilinear appearance.
The term fisheye was coined in 1906 by American physicist and inventor Robert W. Wood based on how a fish would see an ultrawide hemispherical view from beneath the water (a phenomenon known as Snell's window). Their first practical use was in the 1920s for use in meteorology to study cloud formation giving them the name "whole-sky lenses". The angle of view of a fisheye lens is usually between 100 and 180 degrees while the focal lengths depend on the film format they are designed for.
Mass-produced fisheye lenses for photography first appeared in the early 1960s and are generally used for their unique, distorted appearance. For the popular 35 mm film format, typical focal lengths of fisheye lenses are between 8 mm and 10 mm for circular images, and 15–16 mm for full-frame images. For digital cameras using smaller electronic imagers such as 1/4" and 1/3" format CCD or CMOS sensors, the focal length of "miniature" fisheye lenses can be as short as 1 to 2mm.
These types of lenses also have other applications such as re-projecting images filmed through a fisheye lens, or created via computer generated graphics, onto hemispherical screens. Fisheye lenses are also used for scientific photography such as recording of aurora and meteors, and to study plant canopy geometry and to calculate near-ground solar radiation. They are also used as peephole door viewers to give the user a wide field of view.
Usage examples of "fisheye lens".
In this way, a narrow beam of any color can be shot out of the innards of the computer, up through that fisheye lens, in any direction.
For twenty State years CARM #6 had been taking pictures, not just through the CARM cameras but through the fisheye lens on the pressure suit too.
Cuyler through a fisheye lens which he had installed in the door some hours earlier.
Yet she hesitated to move directly to it and peer through the fisheye lens because she feared seeing an eye pressed to the other side, trying to peer in at her.
Through the fisheye lens in the otherwise opaque rear window: a steel whale was brushing past the second camper.
Each door had been fitted with a fisheye lens to allow the resident to examine a caller before deciding whether or not to admit him.
The atmosphere is so thick that it warps light like a fisheye lens.
The scanner was floating high and wide but the fisheye lens relayed enough data for the monitor to compensate.
Inside it, distorted as though seen through a fisheye lens or the bottom of a bottle, was the Great Hall of Unseen University.