a two step process allows a multiple holographic lens to be recorded with a single exposure . a multiple exposure , non - overlapping holographic fly &# 39 ; s eye lens is first prepared with the correct f number spacing . a single collimated beam striking the fly &# 39 ; s eye lens results in a multiple refracted beam array which is allowed to interfere with a second reference beam on a photographic plate . the resulting multiple holographic lens will have equal intensity playback beams , no distortion cross product terms , and improved optical efficiency over multiple superimposed exposure lenses .