In contrast to tinting, toning is not the simple immersion of a film into a dye bath but involves a chemical reaction converting the silver image. In this reaction the neutral silver image in the emulsion of the positive film is replaced by one consisting of colored metal compounds. These were usually iron ferrocyanide (Prussian Blue) for blue, copper ferrocyanide for red/brown, silver sulfide for sepia or rarely uranium ferrocyanide for reddish brown. Toning had been used in still photography before. But since film was projected on the screen it required translucent toning compounds.
Photographs of unidentified color film technologies. Several different principles and times. Feel free to contact us if you can help identifying them!
Hongarije (FRA 1926, Anonymous). Credit: EYE Film Museum. Photographs of the tinted, toned and stencil colored nitrate print by Olivia Kristina Stutz, ERC Advanced Grant FilmColors.
Source: Pénichon, Sylvie (2013): Twentieth Century Colour Photographs. The Complete Guide to Processes, Identification & Preservation. London, Los Angeles: Thames & Hudson, p. 103.
Magic Fire (USA 1955, William Dieterle), item no. DIF 2.04.35.14. Credit: Deutsches Filminstitut DIF. Photograph of the safety print by Barbara Flueckiger.
Magnification of an image area. Source: Eggert, John (1932): Kurzer Überblick über den Stand der Farbenkinematographie. Bericht über den VIII. Internationalen Kongress für wissenschaftliche und angewandte Photographie, Dresden 1931, pp. 214-222. Leipzig: J. A. Barth.
Pénichon, Sylvie (2013): Twentieth Century Colour Photographs. The Complete Guide to Processes, Identification & Preservation. London, Los Angeles: Thames & Hudson, p. 95.
Unidentified Processes from the Kodak Film Samples Collection and the Cinematography Collection.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard, SNSF Film Colors.
Pénichon, Sylvie (2013): Twentieth Century Colour Photographs. The Complete Guide to Processes, Identification & Preservation. London, Los Angeles: Thames & Hudson, p. 209.
Pénichon, Sylvie (2013): Twentieth Century Colour Photographs. The Complete Guide to Processes, Identification & Preservation. London, Los Angeles: Thames & Hudson, p. 138.
Credit: Geo. Willeman, Nitrate Film Vault Manager, Library of Congress. Film: The Magic Isle.
Pénichon, Sylvie (2013): Twentieth Century Colour Photographs. The Complete Guide to Processes, Identification & Preservation. London, Los Angeles: Thames & Hudson, p. 105.
Credit: Cinémathèque française, conservatoire des techniques, Paris.