Electric lamps are mounted by lamp arms to lamp pulleys that are, in turn, mounted to a rigid frame. A motor-driven belt synchronously rotates the lamps via frictional contact with the lamp pulleys to position the lamps to optimally illuminate a target surface. The lamps can be synchronously moved from a first location outside the periphery of the frame to a second location within the frame periphery by operation of the motor driving the belt. In either location, as well as in any other location, the apparatus provides an un-impeded, pass-through opening within the frame for an un-impeded line of sight to the target surface. Furthermore, the radial distance from each lamp to the geometric center of the frame remains the same, and the lamps remain spaced equally apart from each other.