Optical system for a fresnel lens light, especially for a spotlight or floodlight

摘要

The optical system for the Fresnel lens light has an ellipsoidal reflector ( 1 ), a light source ( 2 ) and a Fresnel lens ( 3 ). The distance (a) between the Fresnel lens ( 3 ) and the reflector ( 1 ) is changeable but is related to the changeable distance (b) between the light source ( 2 ) and the reflector ( 1 ) so that the aperture angle of the propagated light beam is variable but illumination intensity of the propagated light is maintained uniform. Surfaces of the at least one Fresnel lens and/or the reflector can be structured to provide more uniform illumination of a given area. The optical system is useful for lights for film, stage, studio and photography.