Agfa Agfacolor

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Agfacolor is the brand name for color photographic materials from Agfa from 1932 (1932–1937 grain raster films and plates, 1933–1936 lenticular films, 1936–1978 reversal films for slides, 1938–2005 negative films for prints on photo paper ).

Agfacolor films have been produced by various Agfa companies, including:

Negative and positive film pouches for Agfacolor, 1952–1965

processing

The Agfacolor films were originally processed using the Agfacolor method; This is also the first process with water-soluble, fat-bound color couplers embedded in the film layers and the first negative / positive process with chromogenic development for cinema films and color photo paper.

history

Technical development

Agfacolor new roll film and 35mm film 1937

Agfa was considered a pioneer in color photography . As early as 1932, the first Agfacolor color film based on the grain grid method was presented. In 1933 Agfacolor lenticular lens film followed as the first 35mm film for color photographs (slides), which was preceded by a corresponding narrow film with an image width of 16 mm in 1932. In 1936 Agfa brought the Agfacolor-Neu film onto the market, making it the first modern color film with incorporated color couplers, that is: It consists of three light-sensitive gelatin layers on top of each other with the color couplers stored in them - in contrast to the Kodachrome films . The three layers are sensitized (from top to bottom) to blue, green and red. Since the silver bromide and iodide crystals in the green and red sensitized layers are also sensitive to blue light, there is a yellow filter layer between the blue and green layers which absorbs the remaining blue light and whose color is washed out during development.

Agfacolor Neu (1936), Hungary 1939

The Agfacolor-Neu-Film was first available as reversal film for slides, followed by narrow film. Here, the latent negative present after exposure is first developed as a black and white image, in order to then cover up the undeveloped silver salt that is still present by post-exposure of the film. The color is then developed by N, N-diethyl-p-phenylenediamine (T22), which forms the actual dyes with the previously colorless color couplers oxidized by the silver salt . The silver, which is reduced from the silver salt during the first development and color development, is oxidized with potassium ferricyanide ( red blood liquor salt ) and dissolved out, so that ultimately only the positive of dye particles remains. The photosensitivity was only nominally ISO 4/7 °, significantly less than that of black and white films of that time.

In 1938 the sensitivity was increased to ISO 16/13 ° (nominal: 15/10 ° DIN) by adding traces of gold rhodanide (approx. 10 µg per film), making the film more suitable for handheld photography without a tripod. The production of paper enlargements was only possible with special processes using color separations.

The Agfacolor motion picture film was the first to use the negative / positive process with chromogenic development. During the development in one step, the color couplers and the color developer produce the complementary colors yellow, magenta and cyan . The result is a negative from which positive images (on Agfacolor paper) and films for demonstration (on Agfacolor positive film) could be produced by copying.

In 1942 the Agfacolor negative photo film and Agfacolor photo paper, which were only available for propaganda and military purposes until the end of the war , were presented at the film and color conference in Dresden . Kodak's Kodacolor , a film with basically the same structure, also came onto the market in 1942, but with a processing process that was not compatible with Agfacolor. The difference was in the way the color couplers were anchored in the three photographic layers. While Agfa relied on diffusion- proof molecules with long saturated hydrocarbon chains similar to fatty acids that could not migrate into the adjacent gelatin layer, Kodak used tiny oil droplets in the gelatin , i.e. oil-protected, water-insoluble color couplers. This process has long since established itself generally for color slide and negative films.

Agfacolor in the cinema

Agfacolor also found its way into German film production from 1939. The success of the US Technicolor system with box office knobs like Robin Hood and Gone with the Wind provided the impetus for this. For reasons of prestige and to demonstrate the efficiency of the German film industry even in times of war, the technical development was pushed forward quickly. The first full-length German film to be filmed in Agfacolor was called Women Are Better Diplomats . It was created between 1939 and 1941 and showed a relatively immature color implementation. During the production of a number of other color films, the Agfacolor process was continuously improved. At the latest with Münchhausen , which premiered in 1943 for the 25th Ufa anniversary , Agfacolor was able to catch up with the technically much more complex Technicolor process in terms of image quality. By the end of the war in 1945, a total of 13 full-length color films were made in Germany: Die goldene Stadt (1942), Das Bad auf der Tenne (1943), Immensee (1943), Münchhausen (1943), The woman of my dreams (1944), Sacrifice (1944) , Große Freiheit No. 7 (1944) and Kolberg (1945). These include the defector films from 1944/1945 Wiener Mädeln , Das kleine Hofkonzert , Ein toller Tag and Die Fledermaus (1946), which were made ready for screening by DEFA (GDR) after the war . After numerous cinema films had been produced in Agfacolor until the 1960s, when the Agfa-Gevaert Group was formed in 1964, the Belgian branch was given responsibility for cinema color film materials, which came onto the market under the Gevacolor and then Agfa XT brands eventually no longer followed the Agfacolor process. VEB Filmfabrik Wolfen in the GDR also renamed its Agfacolor films to Orwocolor in 1964.

Development after 1945

Early color photo on Agfacolor negative film L NT, Eckernförde Bay in summer 1952.

After the Agfacolor recipes were published and the Agfacolor process was compulsorily released in 1945, several manufacturers (Adox, Ferrania, Fuji , Gevaert , Konishiroku (now Konica ), Tellko, Valca) produced such films and photo papers, although the development processes varied were different depending on the manufacturer. From 1978, starting with the highly sensitive Agfacolor CNS 400 negative film, Agfa-Gevaert switched to Kodak chemistry (oil-protected, water-insoluble color couplers), so that Agfa and Kodak color films could be processed in the same development processes, the C-41 that still exists today for negatives or E-6 for slides. This changeover to Kodak chemistry consequently took place with color negative and color slide films as well as with color papers. The changeover brought a significant gain in sharpness, fine grain and quality of color reproduction for the films. The processing time in 38 ° C warm baths was significantly reduced compared to the development times of Agfacolor / Agfachrome films at 18 to 25 ° C. At the same time, well-known traditional products such as the Agfacolor CNS and Agfacolor CT18 slide film disappeared from the market. The old Agfa processes can still be developed today in some specialist laboratories in the UK and USA.

The brand name Agfacolor was used for color negative films until the bankruptcy of AgfaPhoto GmbH, which was separated from the Agfa-Gevaert group in 2005. The most recently produced Vista / Optima films were certified in tests in photo magazines with maximum color fidelity and insensitivity to color shifts, for example due to fluorescent tube light . In the meantime, however, products from the former competitor Fuji are sold under the brand name (imprinted “Made in Japan”).

The last products included:

  • The professional color negative films of the so-called Agfa triad system introduced in the early 1990s : Agfacolor Portrait (for portraits), Agfacolor Optima (for landscape photos ), Agfacolor Ultra (high color saturation).
  • The color reversal film RSX-II . Is still produced today by the Belgian Agfa-Gaevert as a professional aerial photo film Aviphot , which is sold under the Rollei brand with the name Digibase .
  • The Agfacolor HDC .
  • The two amateur films Agfacolor Vista (color negative; under this name still sales of original Agfa material, since the appendage of the name plus it is Fuji material) and Agfa Precisa (color slide film; contains Fuji Provia since the original Agfa material was sold today ).

Resolving power

The graininess is reported as an RMS value . The resolving power was measured at various object contrasts (1.6: 1 and 1000: 1) and is given in lines per millimeter.

Film type Graininess ( RMS ) Resolving power in L / mm with object contrast
1.6: 1 1000: 1
Agfacolor XRG 100 4.5 50 130
Agfacolor XRS 1000 Prof. 8th 40 100

See also

literature

  • Kurt v. Holleben: Color photography with Agfacolor Ultra films and Agfacolor plates. Heering, Harzburg 1935.
  • Eduard v. Pagenhardt (Ed.): Agfacolor, the colored light image. Knorr and Hirth, Munich 1938.
  • Heinz Berger: Agfacolor W. Girardet, Wuppertal 1950.
  • Gert Koshofer: History of color photography in the time of popularization. in: color in the photo. The history of color photography from 1861 to 1981. Catalog for the exhibition in the Josef Haubrich-Kunsthalle Cologne 1981, pp. 133–156.
  • Gert Koshofer: color photography. 3 volumes, Laterna magica, Munich 1981.
  • Guido Wenzel: The beginnings of color cinema in Germany with special consideration of the Agfacolor process and the first color feature films. (= Diploma thesis at the Ludwig Maximilian University in Munich 1991).
  • Gert Koshofer: The Agfacolor story. in: Weltwunder der Cinematographie - Contributions to a cultural history of film technology. 5th edition 1999. Published by Joachim Polzer, Potsdam 1999, ISBN 3-934535-01-1 .
  • Dirk Alt: From demonstration to representation film. The Agfacolor color film process in cinema format 1937–1941. In: Filmblatt. 17th year, No. 48, spring 2012, ISSN  1433-2051 , pp. 55-65.
  • Dirk Alt: “Color film is marching!”: Early color film processes and Nazi propaganda 1933–1945 . belleville, Munich 2013.
  • Dirk Alt / Karl Stamm: Quality improvement for German color film. A color educational film for filmmakers in 1944/45. In: Filmblatt. Volume 19, No. 54, summer 2014, ISSN  1433-2051 , pp. 54-66.

Individual evidence

  1. ↑ Information according to the data sheets of the manufacturer and the University of Basel ( Memento of March 25, 2006 in the Internet Archive ) (PDF).

Web links