Barn oors, or colloquially a set of barn doors, are an attachment fitted to the front of a Fresnel lantern, a type of spotlight used in films, television, and theatres. The attachment has the appearance of a large set of barn doors, but in fact there are four leaves, two larger and widening on the outside, two smaller and getting narrower towards the outside. They facilitate shaping of the beam of light from the fixture, and prevent the distinctive scatter of light created by the Fresnel lens from spilling into areas where it is not wanted, such as the eyes of audience members.