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.
“In 1930 Mannes and Godowsky were invited to join the staff of the Kodak Research Laboratory, where they concentrated on methods of processing multilayer films, while their colleagues worked out ways of manufacturing them. The result was the new Kodachrome film, launched in 1935. Three very thin emulsion layers were coated on film base, the emulsions being sensitised with non-wandering dyes to red, green and blue light, the red-sensitive layer being at the bottom.” (Coe, Brian (1978): Colour Photography. The First Hundred Years 1840-1940. London: Ash & Grant, pp. 121 ff.)