A fisheye lens is an ultrawide-angle lens that produces strong visual distortion intended to create a wide panoramic or hemispherical image. Much like that of looking through a fish bowl.

A fisheye lens is an ultrawide-angle lens that produces strong visual distortion intended to create a wide panoramic or hemispherical image. They come in two types. Circular fisheye lenses project a 180 degree view onto a circle on the image plane. Full-frame fish-eye lenses enlarge this circle to cover the whole image plane.