Source Four Leko

Overview

The "Source Four Leko" is an ellipsoidal reflector spotlight (ERS) from the Source Four series by US manufacturer ETC (Electronic Theatre Controls). "Leko" is not an ETC product name itself, but rather the common generic term for ellipsoidal reflector spotlights used in North America – it derives from Century Lighting founders Joseph Levy and Edward Kook, whose "Lekolite" established the fixture type in 1933. The term has evolved into a quasi-generic term for all ERS fixtures; "Source Four Leko" therefore simply refers to the classic ellipsoidal reflector spotlight in the Source Four range (Tungsten/Halogen).

In contrast to Fresnel or plano-convex spotlights, the ellipsoidal reflector spotlight produces a sharply definable, easily shapeable beam of light. Internal shutters allow the beam to be precisely cut, and gobos or patterns inserted into the gobo slot are projected. On set, it is used for clearly defined light fields, lighting effects, and patterns (gobos).

Construction and Function

• Interchangeable Lens Tubes: The beam angle is defined by interchangeable lens tubes with a fixed beam spread; zoom and EDLT variants are also available. Changing them is tool-free and done by hand.
• Shutters: A rotating shutter assembly with stainless steel blades (three planes) allows for hard cutting of the light field.
• Gobo/Pattern Slot: Holder for gobos for pattern projection and iris diaphragms.
• Color Frame: Front holder for gels (color, diffusion).
• Dichroic Reflector: According to ETC, the faceted dichroic reflector directs approximately 90% of the infrared (heat) radiation out of the beam, thereby protecting gels, gobos, and shutters from thermal stress.

Technical Specifications

Note: The exact color temperature and lifespan depend on the specific HPL lamp type (mains voltage 115 V / 230 V, standard vs. long-life version). When used alongside daylight sources, the warm tungsten characteristic of the HPL lamp needs to be accounted for with conversion gels or white balance.

On-Set Use

On film and TV sets, as well as in theater and studios, the Source Four ellipsoidal reflector spotlight is used wherever a precisely defined light field is required: controlled spots on actors or props, effect lighting through projected gobo patterns (windows, blinds, leaves), and cleanly defined light edges without spill light. Since the interchangeable lens tube determines the beam angle, the same body can be adapted to different throw distances by swapping the tube. According to ETC, the HPL lamp at 575 W achieves the light output of conventional 1000 W ERS fixtures, making the Source Four more energy-efficient than older tungsten ERS fixtures.