Lenticular process

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A lenticular process is a purely optical photographic process of color photography that works according to additive color mixing ; In contrast to the grain grid and line grid processes, no dye particles are used.

functionality

In the case of a camera , a film camera or a projector that work according to the lenticular process, there are color filters in or in front of the lens , each with a blue, green and red color stripe. Lenticular structures are embossed into the substrate of the photographic film to be exposed , through which the images are reproduced in the form of juxtaposed, linear, alternating blue, green and red stripes ( color separations ); this creates a kind of optical line grid.

When the film is projected, the light then only falls through the light stripes of the layer and is deflected by the embossed "lenses" onto the respective stripe segment and thus "colored". The principle of additive color mixing creates the impression of a colored image on the print or canvas .

"When you just looked at the film, of course, it only looked black and white. On closer inspection, however, you could see the fine corrugation of the lens on the back of the layer. The lenticular screen film was only intended for projection, and color images in magazines and books are therefore seldom found "

Examples of line screen films are:

History and Development

The foundations of color photography go back to experiments by James Clerk Maxwell in 1861 , which were based on the theories about the physiological basis of color perception developed by Thomas Young at the beginning of the 19th century . The first practical applications for photography were developed by Louis Ducos du Hauron (1837–1920) and Charles Cros (1842–1888) and Frederic Ives (1888).

Early additive methods of color photography were developed with the color grid plate by James W. McDonough (1892) and the line grid method by John Joly (1894).

The lenticular process is based on fundamental developments by the British FM Machester (1895) and the German Julius R. Ed. Liesegang (1896) and was perfected by the French Rodolphe Berthon and Albert Keller-Dorian as the Berthon / Keller-Dorian method around 1911.

The lenticular film was from the mid-1920s to the introduction of multi-layer films according to the chromogenic method (1935-36), especially for slides agfacolor and narrow films ( 16 mm film Kodak Kodacolor Lenticular ) as well as for films (z. B. Opticolor ) used.

The Kodacolor lenticular lenticular film from (depending on the source: 1925 or 1928) is a black and white film that produces a reversal positive and is provided with a network of regular vertical grooves; the color reproduction during projection is achieved by filters. It is said to have been produced by 1937.

For the Agfafilm there was a special filter set from Leica for the Hektor 1: 1.9 and also a film strip projector. The Contax company produced the color tessar . The film was sold in 18 cartridges in 1933 and had to be exposed 15 to 20 times longer than the b / w film material of the time.

See also

Further photographic processes after additive color mixing:

literature

  • Joachim Polzer (Hrsg.): Weltwunder der Cinematographie (5th edition 1999). Polzer Media Group, Potsdam 1999. ISBN 3-934535-01-1
  • Joachim Polzer (Hrsg.): Weltwunder der Cinematographie (6th edition 2002). Polzer Media Group, Potsdam 2002. ISBN 3-934535-20-8

Individual evidence

  1. ↑ 1. Historical overview. (PDF) abmt.unibas.ch, archived from the original on May 19, 2006 ; accessed on July 16, 2019 .