Fisheye Lens

Fisheye lenses are wide-angle lenses that take a very wide hemispherical image. Originally fisheye lenses were developed for use by meteorologists to study cloud formations and were originally called "whole sky lenses". From a photography standpoint, they became popular because of the distorted curved image they produce. Many photographers utilize fisheye lenses to suggest the curvature of the Earth. They are also used to estimate solar radiation and characterize plant canopy geometry when looking up at the sky.