Gobo (spectacle)

A gobo is an object placed inside or in front of a light source to control the shape of the emitted light and its shadow. For studio photography purposes, the term "gobo" has come to refer to any device that casts a shadow, and various pieces of equipment that go in front of a light (such as a gobo arm or gobo head). In theatrical lighting, however, the term more specifically refers to a device placed in "the gate" or at the "point of focus" between the light source, called a lamp, and the lenses (or other optics). The Oxford Dictionary gives three definitions (and others concur): "A dark plate or screen used to shield a lens from light; (in a theatre) a partial screen used in front of a spotlight to project a shape; shield used to mask a microphone from extraneous noise." Though the Oxford provides a possible "1930s ... unknown origin, perhaps from go between", the exact derivation of gobo is unclear. It may be an American slang abbreviation of "go-between", or "go-before" (just as New York's "SoHo" signifies the area "South of Houston Street"). The term can be traced back to the cinema studios of the 1930s. Some lighting professionals believe that it is an acronym for "goes before optics" or, less often, "goes between optics". An alternative abbreviation might be "graphical optical black-out". The treatment of the word as an acronym is recent, as alternative to applications in optics, "gobo" may refer to a screen or sheet of sound-absorbent material for shielding a microphone from sounds coming from a particular direction (so therefore contrary to an interpretation that deals with visual "black-out" or "optics"). There are many examples of acoustic gobos. See also Gobo (recording). In the photographic industry, a "gobo" describes any opaque, usually black, panel, or "flat", of any dimension, that goes between a light source and photographic subject (such as between sun light and a portrait model) to control the modelling effect of the existing light or, used as a "cutter", to create shadows; or even to control reflections; or between light source and lens, to cut flare.