Recording lightspace so shadows and highlights vary with varying viewing illumination.

Methods are proposed to record the way in which objects respond to varying illumination—to capture and reproduce varying shadows and highlights and thus give the illusion that absent objects are present behind a ‘‘window’’ into which people may shine arbitrary lights of their choice. When the recording is viewed under two separate point sources, one sees a reproduction of the original scene with double shadows. When it is viewed outdoors, on an overcast day, one sees a reproduction of soft or almost nonexistent shadows, whereas the reproduction of the objects themselves remains sharply defined, regardless of the viewing illumination.  1995 Optical Society of America