Source Four

The Electronic Theatre Controls (ETC) Source Four (also known unofficially as Source 4 or S4) is an ellipsoidal reflector spotlight (ERS) used in stage lighting. First released in 1992, the Source Four was invented by David Cunningham and features an improved lamp and reflector compared to previous ERS designs, tool-free lamp adjustment, and a rotating, interchangeable shutter barrel. The Source Four is widely used by professional theaters in the United States.

Read more about Source Four:  Glass Reflector, Lamp Adjustment, HPL Lamp, HID, Barrel, Enhanced Definition Lens Tube, Third Party Offerings, Other Source Four Products

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