Dual film
n.phr.
Subject Field: Cinematography

The dual film technique employs a dual film camera and beam splitter. A color negative records the action, and a black & white film records a matte (silhouette) of the action. The backing behind the actor requires special illumination which will expose the B & W matte film, but will not expose the separate color negative. Various illuminators have been used including Ultraviolet, Infrared, and Sodium. Ryan			See Instrument Beam-splitting camera - Hyperonyms - Traveling matte shot - Hyponyms - Blue screen process Infrared process Ultraviolet process Bibliography Index Home Conceptual tree
Context: The sodium system is by far the most-used dual film matte system. As originally used in England, it required a backing illuminated by monochromatic sodium light. Didymium glass filters were required on all set lamps to subtract the sodium wavelength from the foreground lighting. Ryan Attestation: 3 Film doppio Reliability: 3