Abstract: A lighting system for projecting a beam of light has a light source and a concave reflector having a central axis. The center of the light source is located at a position other than at the focal point of the reflector, i.e. between the reflector surface and the focal point of the reflector for an ellipsoidal reflector and forward of the focal point for a parabolic reflector. This placement provides a greater light output than is achievable by positioning the light source at the focal point of the reflector. The preferred light source is an improved lamp having an incandescent filament having a central linear helical portion aligned with a central axis of the reflector and a peripheral helix portion around the central portion so as to concentrate the emission of light along and about the central axis of the filament.

Abstract: A performer tracking system, and an associated method, for tracking movements of at least one performer upon a stage. A plurality of signal transmitters are positioned about the stage and transmit electromagnetic signals. Performers on the stage carry transponders which receive the electromagnetic signals and, responsive thereto, generate coded sound signals. Sound signal receivers positioned together with the signal transmitters receive the sound signals. A controller determines positions of the transponders and, hence, the performers carrying the transponders and causes spotlights to track the performers.