“Douglass Color No. 2 (1919). The two negatives of the Douglass Color system No. 1 were printed on a positive. In this updated version of the process, rather than projecting the frames through red and green filters, both latent images were ...

“Polychromide, a two-color subtractive process invented in 1918 by Aron Hamburger, achieved limited commercial success overseas, and was occasionally employed in England as late as 1933. Originally an orthochromatic and a panchromatic negative were ...

“Two-colour additive process Talkicolor was developed by Percy James Pearce along with Dr Anthony Bernardi who was also involved in the development of Raycol. The process was funded mainly by the author Elinor Glyn through her company Elinor ...

“Following the premises of one of William Friese-Greene’s systems, this two-colour subtractive process required that two reels of film be printed in parallel through a lens fitted with a prism that split light in two directions, through red ...

The Kodachrome process was invented in 1913 by John G. Capstaff for still photography and subsequently adapted to motion pictures. For the process two frames were advanced simultaneously, one located above the other. The light passed either through two lenses or through a beam-splitter, fitted with red and green filters. The release print was exposed through a beam-splitter whereby the alternate frames were projected onto either side of double-coated stock. After development by a usual b/w process, the film was tanned to harden the exposed areas. The soft areas were dyed red-orange and blue-green respectively.

“The principle of the subtractive colour process was described first by Louis Ducos du Hauron in 1868. Although eminently suitable for colour motion pictures, the principle could not be applied until means were found of producing several colour ...

“R. Berthon and M. Audibert patented a method of obtaining a virtual image by means of an anterior lens and prisms or mirrors. This idea was further improved upon in E.P. 17,023, 1913. In F.P. 458,040 Audibert proposed to use a negative front lens ...

“M. F. de Colombier appears to have been the first to suggest the application of this system to cinematography, and like so many French patents it is a little indefinite in phraseology. Three films were employed representing the same view and ...

“To offset the possible effects of poor contact between the various members of the tripack, J. H. Smith coated the emulsions directly one on top of the other, but with an insulating layer of collodion between them. In this manner there was ...

“A. Gurtner (Eng. P. 7924/03; U.S.P. 730454), used a front element that was sensitive only to the blue, and a rear element that was sensitive up to but not including the red. He was the first person to suggest that the two films or plates be ...