Please access detailed information on over 250 individual film color processes via the classification system on this page, display the Timeline of Historical Film Colors in chronological order, search via the tag cloud at the end of this page or directly on the search page, or see the contributing archives’ collections on the header slides.
Since the earliest days of cinema, film has been a colorful medium and art form. More than 230 film color processes have been devised in the course of film history, often in close connection with photography. In this regard, both media institutionalized numerous techniques such as hand and stencil coloring as well as printing and halftone processes. Apart from these fundamental connections in terms of the technology of color processes, film and photography also share and exchange color attributions and aesthetics.
This publication highlights material aspects of color in photography and film, while also investigating the relationship of historical film colors and present-day photography. Works of contemporary photographers and artists who reflect on technological and culture-theoretical aspects of the material of color underline these relations. Thematic clusters focus on aesthetic and technological parallels, including fashion and identity, abstraction and experiment, politics, exoticism, and travel.
Color Mania contains a general introduction to color in film and photography (technique, materiality, aesthetics) as well as a series of short essays that take a closer look at specific aspects. An extensive image section illustrates the texts and color systems and continues the aesthetic experience of the various processes and objects in book form.
Edited by Barbara Flückiger, Eva Hielscher, Nadine Wietlisbach, in collaboration with Fotomuseum Winterthur
With contributions by Michelle Beutler, Noemi Daugaard, Josephine Diecke, Evelyn Echle, Barbara Flueckiger, Eirik Frisvold Hanssen, Eva Hielscher, Thilo Koenig, Joëlle Kost, Franziska Kunze, Bregt Lameris, David Pfluger, Ulrich Ruedel, Mona Schubert, Simon Spiegel, Olivia Kristina Stutz, Giorgio Trumpy, Martin Weiss, Nadine Wietlisbach
Design: Meierkolb
16 × 24 cm, 6 ¼ × 9 ½ in
240 pages, 122 illustrations
paperback
This database was created in 2012 and has been developed and curated by Barbara Flueckiger, professor at the Department of Film Studies, University of Zurich to provide comprehensive information about historical film color processes invented since the end of the 19th century including specific still photography color technologies that were their conceptual predecessors.
Timeline of Historical Film Colors was started with Barbara Flueckiger’s research at Harvard University in the framework of her project Film History Re-mastered, funded by Swiss National Science Foundation, 2011-2013.
In 2013 the University of Zurich and the Swiss National Science Foundation awarded additional funding for the elaboration of this web resource. 80 financial contributors sponsored the crowdfunding campaign Database of Historical Film Colors with more than USD 11.100 in 2012. In addition, the Institute for the Performing Arts and Film, Zurich University of the Arts provided a major contribution to the development of the database. Many further persons and institutions have supported the project, see acknowledgements.
Since February 2016 the database has been redeveloped in the framework of the research project Film Colors. Technologies, Cultures, Institutions funded by a grant from Swiss National Science Foundation. Since 2016, the team of the research project ERC Advanced Grant FilmColors has been collecting and adding written sources. All the members of the two research projects on film colors, both led by Barbara Flueckiger, have been capturing photographs of historical film prints since 2017.
Follow the links “Access detailed information ›” to access the currently available detail pages for individual processes. These pages contain an image gallery, a short description, a bibliography of original papers and secondary sources connected to extended quotes from these sources, downloads of seminal papers and links. We are updating these detail pages on a regular basis.
In June 2015, the European Research Council awarded the prestigious Advanced Grant to Barbara Flueckiger for her new research project FilmColors. Bridging the Gap Between Technology and Aesthetics, see press release of the University of Zurich and information on the University of Zurich’s website.
Subscribe to the blog to receive all the news: https://blog.filmcolors.org/ (check out sidebar on individual entries for the “follow” button).
Contributions to the Timeline of Historical Film Colors
“It would not have been possible to collect all the data and the corresponding images without the support from many individuals and institutions.Thank you so much for your contribution, I am very grateful.”
Barbara Flueckiger
Experts, scholars, institutions | Sponsors, supporters, patrons of the crowdfunding campaign, April 23 to July 21, 2012
Experts, scholars, institutions
Prof. Dr. David Rodowick, Chair, Harvard University, Department of Visual and Environmental Studies
Prof. Dr. Margrit Tröhler, Department of Film Studies, University of Zurich
Prof. Dr. Jörg Schweinitz, Department of Film Studies, University of Zurich
Prof. Dr. Christine N. Brinckmann, Department of Film Studies, University of Zurich
PD Dr. Franziska Heller, Department of Film Studies, University of Zurich
Dr. Claudy Op den Kamp, Department of Film Studies, University of Zurich
Prof. Anton Rey, Institute for the Performing Arts and Film, Zurich University of the Arts
Dr. Haden Guest, Director, Harvard Film Archive
Liz Coffey, Film Conservator, Harvard Film Archive
Mark Johnson, Loan Officer, Harvard Film Archive
Brittany Gravely, Publicist, Harvard Film Archive
Clayton Scoble, Manager of the Digital Imaging Lab & Photography Studio, Harvard University
Stephen Jennings, Photographer, Harvard University, Fine Arts Library
Dr. Paolo Cherchi Usai, Senior Curator, George Eastman Museum, Motion Picture Department
Jared Case, Head of Cataloging and Access, George Eastman Museum, Motion Picture Department
Nancy Kauffman, Archivist – Stills, Posters and Paper Collections, George Eastman Museum, Motion Picture Department
Deborah Stoiber, Collection Manager, George Eastman Museum, Motion Picture Department
Barbara Puorro Galasso, Photographer, George Eastman House, International Museum of Photography and Film
Daniela Currò, Preservation Officer, George Eastman House, Motion Picture Department
James Layton, Manager, Celeste Bartos Film Preservation Center, Department of Film, The Museum of Modern Art
Mike Pogorzelski, Archive Director, Academy Film Archive
Josef Lindner, Preservation Officer, Academy Film Archive
Cassie Blake, Public Access Coordinator, Academy Film Archive
Melissa Levesque, Nitrate Curator, Academy Film Archive
Prof. Dr. Giovanna Fossati, Head Curator, EYE Film Institute, Amsterdam, and Professor at the University of Amsterdam
Annike Kross, Film Restorer, EYE Film Institute, Amsterdam
Elif Rongen-Kaynakçi, Curator Silent Film, EYE Film Institute, Amsterdam
Catherine Cormon, EYE Film Institute, Amsterdam
Anke Wilkening, Friedrich Wilhelm Murnau Foundation, Wiesbaden, Germany
Marianna De Sanctis, L’Immagine Ritrovata, Bologna
Paola Ferrari, L’Immagine Ritrovata, Bologna
Gert and Ingrid Koshofer, Gert Koshofer Collection, Bergisch Gladbach, Germany
Memoriav, Verein zur Erhaltung des audiovisuellen Kulturgutes der Schweiz
BSc Gaudenz Halter, Software Development Color Film Analyses, video annotation und crowdsourcing platform VIAN, in collaboration with Visualization and MultiMedia Lab of Prof. Dr. Renato Pajarola, University of Zurich, (Enrique G. Paredes, PhD; Rafael Ballester-Ripoll, PhD) since 07.2017
BSc Noyan Evirgen, Software Development, in collaboration with Visualization and MultiMedia Lab von Prof. Dr. Renato Pajarola, Universität Zürich (Enrique G. Paredes, PhD; Rafael Ballester-Ripoll, PhD), 03.2017–01.2018
Assistants Film Analyses:
BA Manuel Joller, BA Ursina Früh, BA/MA Valentina Romero
The development of the project started in fall 2011 with stage 1. Each stage necessitated a different financing scheme. We are now in stage 3 and are looking for additional funding by private sponsors. Please use the Stripe interface to pay conveniently online or transfer your financial contribution directly to
Account IBAN CH2509000000604877146
Account holder: Barbara Flueckiger, CH-8005 Zurich, Switzerland
SWIFT Code / BIC: P O F I C H B E X X X
Bank: PostFinance AG, Mingerstrasse 20, CH-3030 Bern, Switzerland
Clearing Nummer: 09000
Read more about the financial background of the project on filmcolors.org.
The author has exercised the greatest care in seeking all necessary permissions to publish the material on this website. Please contact the author immediately and directly should anything infringe a copyright nonetheless.
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
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Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
ShowHide details
Zoechrome samples from the Kodak Film Samples Collection at the National Science and Media Museum in Bradford.
Credit: National Science and Media Museum Bradford.
Photographs by Barbara Flueckiger in collaboration with Noemi Daugaard.
Brown, Simon (2012): Technical Appendix. In: Sarah Street: Colour Films in Britain. The Negotiation of Innovation 1900-55. Basingstoke, Hampshire: Palgrave Macmillan, pp. 259-287, on p. 287. View Quote
Coe, Brian (1981): The History of Movie Photography. Westfield, N.J.: Eastview Editions, pp. 130-131. View Quote
Eggert, John (1932): Kurzer Überblick über den Stand der Farbenkinematographie. In: Bericht über den VIII. Internationalen Kongress für wissenschaftliche und angewandte Photographie, Dresden 1931. Leipzig: J. A. Barth, pp. 214–221, on pp. 215–218. (in German) View Quote
Klein, Adrian Bernhard (Cornwell-Clyne) (1940): Colour Cinematography. Boston: American Photographic Pub. Co., p. 20. View Quote
Scotland, John (1931): The Talkies. New York: Industrial Book, pp. 174-178. View Quote
“An English company, Zoechrome, whose film has not yet been seen in public, has attacked this problem in a most ingenious way, and has, moreover, succeeded in achieving something on which Technicolor are still working; that is, putting three colours on the same side of the film. A camera is used having four lenses cemented in a group (three quite small, and one ordinary size) which photograph four different images of the same aspect at once. The three small lenses have behind them the three necessary colour screens, red, green, and violet-blue, which photograph their respective colour factors simultaneously, but not overlapping on to the space of the one ordinary sized picture. Each colour screen picture is one quarter the size of an ordinary film picture. The fourth lens gets over the trouble mentioned previously, of lack of definition, by photographing an ordinary black and white picture which acts, as it were, as an optical key on which to superimpose the colour images. The fact that four lenses are used instead of one, and that a very ingenious modification has been made to the shutter, makes it possible to do away with the extra lighting usually associated with colour work. The camera can be turned at the speed and under the same lighting conditions as an ordinary cinecamera – a tremendous advantage over other methods. The illustration shows a Zoechrome negative. The coloured positive, of course, in a black and white illustration, would be no different from an ordinary black and white film.
The negative is developed in the usual way, fixed and dried. In printing Zoechrome have again departed radically from ordinary procedure. A projection printer is used, which projects the images from the negative on to the positive, which is in another mechanism, much as an ordinary enlarger treats a snapshot, or a magic lantern throws a slide on to a screen. The black and white key picture of normal size is printed first, the negative mechanism pulling down two picture spaces to the positive mechanism’s one. The black and white length is then developed to a half-tone depth, that is to say, to form a grey and white picture, with no real black, but only varying shades of grey. It is then fixed, washed, dried, and varnished. The same film is then recoated with fresh light-sensitive emulsion on top of the grey image, and the first colour-sensation negative is enlarged from quarter size to full size, and perfectly superimposed on the top of the half-tone pictures along the whole length. This is then developed, fixed, washed, and toned the complementary colour to the screen through which it was photographed. Thus the negative taken through a red screen produces a positive in varying intensitives of blue-green. The negative of the violet-blue component gives a yellow positive, and that of the green component a magenta positive. It will be seen from the above that each toning colour contains the spectrum minus the colour of the photographing filter.
When the first colour positive has been toned with what is known as a basic dye, as distinct from an aniline dye, the dye is mordanted or fixed, and the silver image is then dissolved out, leaving only the dye behind, which is absolutely transparent.
A second coat of varnish is applied when the film is dry, and a further coat of emulsion applied to receive the second colour; and after this has gone through the same process, yet a third emulsion is applied on which the third colour component is printed in its complementary tone.
All this sounds very complicated, but actually it is automatic throughout, and the final result is no thicker than an ordinary black and white positive, whereas it has everything on one side of the film. It needs no extra strength of light to project it, because all the colours are absolutely transparent, being only dyes and not part of the detail or definition of the picture. All the detail and definition of the picture is contained in the half-tone key; so that the colours are only asked to do their normal job, i.e. to colour the parts which should be coloured.
Imagine it. Four separate emulsions, four separate printings and developings, and three layers of varnish so thin that the finished film is no thicker than an ordinary single-emulsion film.
This process is inevitably slightly more costly than that of ordinary film production, but it entails less anxious ingenuity than the Technicolor process involves.”
(Scotland, John (1931): The Talkies. New York: Industrial Book, pp. 174-178.)
“T. A. Mills patented a three-colour process in September 1921, which was demonstrated in 1929 under the name Zoechrome. Mills proposed a four-lens camera, one lens exposing a single, conventionally sized frame and the other three smaller lenses producing three small colour separation images in the space of the adjacent frame, the film being moved on two frames at a time. The alternate black and white full frame exposures were printed by a ‘skip’ printer in continuous sequence on a film, which was developed to give a conventional black and white print. This was varnished and recoated with emulsion and one of the smaller separation exposures was printed by enlargement in register with the existing image. The new print was dye-toned in the appropriate colour, varnished and recoated, and the second negative set was enlarged onto it, the print dye-toned and revarnished to receive yet another emulsion, and another printing and dye toning. This would seem to be doing things the hard way but the process worked adequately enough and reached the stage of trade demonstrations where it was described as a ‘sound business proposition’. A reviewer said that the colour was ‘as good as any I have seen’. It was claimed that £40,000 had been spent on the development of the process and in 1932 it was offered for sale. There were no takers.”
(Coe, Brian (1981): The History of Movie Photography. Westfield, N. J.: Eastview Editions, pp. 130-131.)
“1920-9. – T. A. Mills was the inventor of a process known as ” Zoechrome ” (E.P. 172,714, 1920). One full frame was succeeded by three small pictures occupying the space of a normal frame. All four pictures were exposed at the same time. The three small pictures were exposed through tri-colour filters, while the large picture was a normal panchromatic record. The black-and-white negative was taken with an F./3·5, 3-inch lens, while the small negatives were made with three lenses of about F./4·0 and of shorter focus, bunched together to reduce parallax, and placed immediately below the main lens. All four lenses were mounted together for focussing. In printing, the alternate full images of the negative are printed in succession; the positive is developed as usual, varnished and then recoated with emulsion. One of the small images is printed by enlargement in register with the full-sized image, developed and dye-toned. The film is again varnished and recoated with emulsion, and the cycle of operations is repeated for the two remaining colours. This process is no longer being worked commercially.”
(Klein, Adrian Bernhard (Cornwell-Clyne) (1940): Colour Cinematography. Boston: American Photographic Pub. Co., p. 20.)
“Zoechrome (1911-32)
Two/three-colour subtractive process
Zoechrome was developed by Thomas Albert Mills over an extended period. He first patented a successive-frame system for two- or three-colour cinematography in December 1911. This was a complicated system in which, for two-colour, successive images were captured through blue and orange filters. After printing the successive frames were toned blue and orange and then the film was coated with emulsion on the back and the same images printed one frame out of register and toned identically, so behind each blue-toned frame on the print was an orange-toned frame. Zoechrome Ltd was registered in February 1912 with a nominal capital of £15,000 in £1 shares to acquire the rights Mill’s patents. From 1921 the process was significantly revised and by the time it was first demonstrated in 1929 it used one large and three smaller lenses. Successive frames were registered, one through the large, normal-sized lens creating a full-frame picture, and the next through the three smaller lenses resulting in three small images registered on a normal-sized frame. This created a negative which alternated between one full-sized frame and one frame with three smaller images. Each single frame image was printed to produce a black-and-white print of the full-frame image. This was then fixed with varnish and then recoated with emulsion. One of the three smaller images was then enlarged and printed over the full-frame image in register. The print was then dye-toned with the correct subtractive colour, and the process repeated with the other two colours. The function of the single, black-and-white full-frame image was effectively to override any parallax issues from the three smaller images, the larger one being much clearer and more dominant.
The first public demonstration of the process took place on 12 March 1929 at the New Gallery in London, featuring footage of the sea, country lanes and flowers. Despite a favourable review the following day in The Times, the company appears to have never traded and an official receiver was appointed in April 1931. When the process was offered for sale in 1932 there were no buyers and it ceased development.
Further reading
BT 31/32118/120350, Zoechrome Ltd, 1912, National Archives.
Coe, Brian, The History of Movie Photography (London: Ash & Grant, 1981), pp. 130-1.
Neale, Steve, Cinema and Technology: Image, Sound, Colour (London: BFI, 1985), p. 123.
Cherchi Usai, Paolo, Silent Cinema: An Introduction (London: BFI, 2000), p. 36.”
(Brown, Simon (2012): Technical Appendix. In: Sarah Street: Colour Films in Britain. The Negotiation of Innovation 1900-55. Basingstoke, Hampshire: Palgrave Macmillan, pp. 259-287, on p. 287.)
“Mit fortschreitender Entwicklung ist die Herstellung des Farbenbildes durch Heranziehung geeigneter photographischer, chemischer oder optischer Hilfsmittel ganz mechanisiert worden. Sie fußen auf der Zerlegung des farbigen Bildes in mehrere Teilfarbenbilder, die in geeigneter Weise kombiniert werden. Man unterscheidet nach der spektralen Auswahl zwei Gruppen farbenkinematographischer Methoden:
1. Die Zweifarbenverfahren,
2. die Dreifarbenverfahren.
Diese teilen sich wieder nach der Farbensynthese in zwei (von der ersten Unterscheidung unabhängige) Gruppen:
1. die subtraktiven Verfahren,
2. die additiven Verfahren.
Wir besprechen zuerst die subtraktiven Methoden und beginnen mit den Zweifarbenverfahren. Die beiden typischen Farbstoffe, die letzten Endes die Farbwirkung hervorrufen, sind ein Orangerot (1) und ein Blaugrün (2). Durch diese beiden Komponenten, ist das Spektrum, grob gesprochen, in zwei Teile zerlegt. Reine rote bis gelbe Töne werden stets durch Farbstoff (1) wiedergegeben; dabei kann natürlich die Anfärbung vom satten Grundfarbstoff bis zum Weiß (unangefärbt) stattfinden. Das gleiche gilt für Farbstoff (2), der die Töne von Grün bis Blau vertritt. Schwarz wird durch räumliche Hintereinanderlagerung beider Farbstoffe (zwischen Lichtquelle und Schirm) gewonnen, denn der blaugrüne Teil des Spektrums wird zunächst durch (1) ausgelöscht und der rotgelbe Teil durch (2) verschluckt.1 Das weiße Licht wird also in 2 Portionen fortgenommen – daher die Bezeichnung “subtraktive Methode”. Die Grauleiter entsteht entsprechend durch Hintereinanderschaltung schwächerer (aber in Summa neutral wirkender) Anfärbungen von (1) und (2), und schließlich besteht die Möglichkeit, durch Kombination verschieden kräftiger Anfärbungen beider Farbstoffe eine relativ umfangreiche Reihe von Mischfarben (z.B. die Fleischfarbe) hervorzubringen. Das Problem besteht nun darin, diese beiden Farbstoffe jeweils in der richtigen Konzentration an die richtigen Stellen der beiden Teilbilder zu bringen, die durch Über- oder Hintereinanderlegung die Gesamtwirkung hervorrufen.
Zur Herstellung der beiden Teilnegative bestehen hauptsächlich zwei Möglichkeiten: die Strahlenteilung und der Zweipack. Wie Abb. 1 an einer schematischen Darstellung des Strahlenteilungsprinzips unter Fortlassung der Linsenoptik zeigt, fällt das vom aufzunehmenden Objekt kommend Licht zunächst auf den halbdurchlässigen Spiegel S. Die eine Hälfte der Strahlung wird reflektiert und erzeugt auf dem (panchromatischen) Film p2 hinter dem Rotorange-Filter F2 ein Bild des Rotorange-Anteils, da das vorgestellte gleichgefärbte Filter die übrigen Lichtarten fortnimmt. Die andere Hälfte der Strahlung geht durch S hindurch und entwirft auf dem Film p1 den Blaugrün-Auszug, weil das eingeschaltete gleichfarbige Filter F1 den komplementären Teil des Spektrums absorbiert. Mit Hilfe der Perforation des Films lassen sich die zusammengehörigen Bilderpaare exakt zu konturgetreuer Deckung bringen, wenn durch die sonstigen optischen Bedingungen der Apparatur identische Abbildungen gesichert sind. Es besteht also auch die Möglichkeit, die auf den Einzelfilmen p1 und p2 erzeugten Bilder durch geeignete Hilfsmittel auf einem gemeinsamen Film untereianderstehend anzuordnen, wobei nach jeder Aufnahme die doppelte Filmlänge wie normal transportiert wird; solche Negative werden nicht im Kontakt, sondern optisch kopiert. – Abb. 2 zeigt die Trennung der Lichtarten nach dem Zweipackverfahren, bei dem die Aussonderung der beiden komplementären Lichtarten durch die verschiedene spektrale Empfindlichkeit der photographischen Schichten erfolgt. Ein blaugrünempfindlicher Frontfilm liegt bei der Aufnahme Schicht an Schicht und im engen Kontakt mit einem rotempfindlichen Schlußfilm. Das Licht tritt in den Zweipack durch das Zelluloid a des Frontfilms ein, gibt auf diesem den Blaugrün-Auszug, während das organgerote Licht auf die Schicht des Schlußfilms d wirkt, nachdem es durch ein mit dem Frontfilm verbundenes Orangefilter c von den Resten der Blaugrünstrahlung befreit wurde. Auch in dieser Anordnung wird durch die Perforation das exakte Aufeinanderpassen der beiden Bilder gewährleistet. Bemerkt sei noch, daß unter Einschaltung eines zweiten halbdurchlässigen Spiegels in die Strahlenteilungskamera oder eines Zwischenfilms beim Dreipack2 der Übergang zur Dreifarbenphotographie möglich ist, da auf diesem Wege (bei Anwendung entsprechender Filter) drei getrennte Farbauszüge herstellbar sind.
Mit Hilfe der auf die eine oder andere Weise gewonnenen beiden Teilnegative ist nun im anschließenden Positivprozeß die Einführung der genannten beiden Farbstoffe zu bewerkstelligen. Dies kann nach zwei Verfahren geschehen. Entweder man stellt von den Negativen auf photographischem Wege oder mit Hilfe des Chromatprozesses Gelatinereliefs her, die man im komplementären Sinne anfärbt und im Absaugeverfahren auf einen Blankfilm mit Gelatineüberzug hintereinander und unter Innehaltung exakter Konturdeckung überträgt; der Orangerot-Auszug liefert also das blaugrün gefärbte Teilbild und umgekehrt, wobei schließlich beide Bilder auf der gleichen Schichtseite des Blankfilms übereinanderliegen. – Oder man kopiert (wie Abb. 2 zeigt) die beiden zusammengehörigen Teilnegative gleichzeitig auf einen zwischen ihnen liegenden doppelseitig begossenen Positivfilm, so daß die entsprechenden Kopien zunächst als Silberbilder auf getrennten Seiten liegen. Verwandelt man diese in Farbstoffbilder durch chemische Tonung (Eisenblau- oder Urantonung) oder durch Virage (z. B. Jodsilberbeizfärbung) wiederum im komplementären Sinne, so ergibt sich ein ebenfalls wie beim Absaugeverfahren, subtraktives Zweifarbenbild. Schließlich kann man auch die Negative oder zweckmäßiger die auf einem doppelseitig beschichteten Film einander gegenüber angeordneten Duplikatnegative in gebleichte Gerbreliefs überführen und zu den Aufnahmefiltern komplementär anfärben. Die nachfolgende Tabelle zeigt, in welcher Weise eine Anzahl bekannter Verfahren die genannten Methoden (in zum Teil etwas modifizierter Weise) kombinieren. In der letzten Spalte der Tabelle wird auf die beiliegende Tafel verwiesen, für die die Firmen Technicolor Motion Picture Corp., Boston, Eastman Kodak Co., Rochester, Multicolor-Films-Inc., Los Angeles, Universum Film. A.-G., Berlin, und “Sirius” Farben-Film Ges.m.b.H., Berlin, einige Probebilder in dankenswerter Weise zur Verfügung gestellt haben.
Dem Multicolor-Verfahren ähnlich sind das Magnacolor-, Polychromide-, Photocolor-, Colorcraft-, Coloratura- und andere Verfahren, die zum Teil die Strahlenteilung als Aufnahmemethode verwenden. Das Harriscolor-Verfahren bedient sich eines einschichtigen Positivfilms und erzeugt die einzelnen Teilbilder in verschiedenen Schichttiefen. Das Foxcolor-Verfahren ist dem Kodachromverfahren analog. Bei dem Zoechrom-Verfahren werden die den einzelnen Teilnegativen entsprechenden Teilbilder auf nacheinander aufgebrachte Schichten nacheinander kopiert, entwickelt und gefärbt.
Bei den subtraktiven Verfahren wird grundsätzlich so vorgegangen, daß von dem ursprünglich weißen Licht durch geeignete Farbstoffe diejenigen spektralen Anteile entfernt werden, die nicht dem aufgenommenen Objekt entsprechen: die gewünschten Bildfarben bleiben als Differenz
übrig.
1 Bei gewisser Farbstoffauswahl bleibt übrigens gelegentlich an Stelle von Schwarz ein Lichtrest in der Tönung von dunkler Sepia zurück.
2 Diese Anordnung wurde bisher nur für die Zwecke der Amateurphotographie, nicht für Kinefilm benutzt.”
(Eggert, John (1932): Kurzer Überblick über den Stand der Farbenkinematographie. In: Bericht über den VIII. Internationalen Kongress für wissenschaftliche und angewandte Photographie, Dresden 1931. Leipzig: J. A. Barth, pp. 214–221, on pp. 215–218.) (in German)