Source Four PAR

The Source Four PAR is a stage lighting instrument manufactured by Electronic Theatre Controls. The name of the fixture derives from the stylistic and construction features it shares with ETC's Source Four. The suffix identifies the Source Four PAR as a parabolic aluminized reflector (PAR). It is designed and marketed as a modern, energy efficient alternative to traditional PAR fixtures used in theatrical and broadcast lighting.

The Source Four PAR is designed to use the same PAR CAN lamp used in other ETC Source Four fixtures. The HPL lamp, combined with newer aluminum reflector technology, is designed to allow for more light output while using a lower wattage. The light output of a 575 watt HPL is listed as comparable to that of a 1000 watt PAR 64. The Source Four PAR can also be fitted with 375, 550, or 750 watt HPL lamps.

The fixture allows for beam and field adjustment using interchangeable lenses, and is designed for "shaping" the output (with the multifaceted lenses) in the same way that traditional PAR bulbs are intended to be rotated inside a fixture for a more horizontal or vertical beam orientation. ETC manufactures five interchangeable glass lenses for this fixture (four come included, while the fifth, the XWFL, is a separate purchase.) This interchangeability of the lenses is often considered an advantage, since traditional PAR fixtures require a stock of different lamps to achieve various beam angles. This allows for a great amount of flexibility from a single fixture.

The shortened barrel of a Source Four PAR (relative to a traditional PAR fixture) makes the light source more visible at a much greater angle. In some cases, this may be considered an unwelcome effect as it can cause lens flare or change the audience's perception of a theatrical scene. top hats or barn doors attach to Source Four PARs to eliminate this source visibility.

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