[This summary of the history of the development of Agfacolor lenticular film is based on a detailed account in In Farbe: Die Agfa-ORWO-Farbfotografie (Finger, 2014), and the sources referenced therein at Bundesarchiv, Koblenz, Germany and the archive of the Industrie- und Filmmuseum Wolfen, Bitterfeld-Wolfen, Germany.]

The company that would become globally known as a producer of photographic products, Agfa, started out in 1867 as Actien Gesellschaft für Anilin-Fabrikation, Berlin – a German chemical company specializing in the production of aniline dyes and stains. Only when they commenced production of photographic products at the end of the nineteenth century, was the name abbreviated to AGFA. 

Agfa first produced photographic materials for color photography in 1916, based on Lumière’s Autochrome process, which used red, green and blue starch grains to capture color information on B/W film. This color system, which gave satisfactory results for still photography, did not work well for moving images [see Cinécolor]. The random distribution of colored grains produced a disturbing “color noise” when applied to motion picture film (Alt, 2011: p. 39). 

In 1925, Kodak bought the rights to produce and sell a 16mm lenticular film from the French Société du Films en Coleurs Keller-Dorian, which exploited the Patents of Rudolph Berthon and Albert Keller-Dorian. The resulting product was branded Kodacolor and was brought to market in 1928.

Also in 1925, a Dr. Kühne, an employee of the dye manufacturer Farbenfabriken vorm. Friedr. Bayer & Co., had witnessed a presentation of Rudolph Berton's lenticular film in Paris and had written to the management at Agfa suggesting that they invite the Société du Films en Coleurs Keller-Dorian to Germany for a presentation of their technology.

In earlier years, Agfa had not pursued lenticular technology to produce a color film as it was considered practically impossible to achieve good-quality results, at scale. In spite of this, Mr. Verola, the director of the Société du Films en Coleurs Keller-Dorian, and his team, were invited to Berlin – subsequently, a sample of film material from Agfa's plant in Wolfen was sent to Paris, to be embossed with lenticules.

Following these events, lenticular color research was initiated under the lead of Prof. John Eggert, head of the scientific department at Agfa. To succeed in bringing a viable product to the market, Agfa had to overcome two major hurdles: first, the technical implementation – ideally surpassing competitors in terms of image resolution and brightness; second, the acquisition of necessary patents, knowing that Kodak had already acquired them for the US and European territories.

Contractual negotiations were initiated between Agfa and the Keller-Dorian company but came to nothing. The legal situation appeared chaotic and Agfa came to the conclusion that existing patents could be circumvented if the company developed its own way to produce lenticular structures in the film base.

Agfa patented its own embossing technology in 1928, with initial projection tests conducted the same year. In the same manner as Kodacolor, Agfa applied the lenticules vertically across the film. Part of Agfa's plan was to develop a system with finer lenticules than Kodacolor, but which was nonetheless compatible for use with Kodak cameras and projectors. Agfa named its new technology Agfacolor (a name later reused for multiple other products from the company).

In 1929, the Agfa Camerawerk Munich delivered German-manufactured optical components to Berlin, for testing. The significant loss of light inherent with lenticular projection was a known issue, so Agfa also developed a special projection screen,with increased reflectivity, which was branded Pelloro Silber, once it was introduced to the market.

Even though Agfacolor Schmalfilm was intended to be a reversal film for the amateur filmmaking market, research work was carried out on a special optical copying process which would make it possible to produce multiple copies of lenticular films. In addition, a photographic slide film was in development.

Agfa was aiming for a lenticular width of 28 µm (0.028mm), significantly smaller than the 43µm (0.043mm) lenticules of Kodacolor. This would distinguish Agfa’s product in terms of image quality and, at the same time, help avoid the issue of patent infringement. However, this made it more complex maintaining compatibility with Kodak products.

The production of a 28 µm lenticular structure proved to be technically complex. It took the specialist wire manufacturer Drahtwerk Rösslau until 1932 to deliver a 28 µm-gauge wire, uniform enough for the embossing process. Further, the thickness of the film base needed to be reduced to 110 µm (0.11mm) to adjust for the shorter focal length of the smaller lenticules. At the same time, the resolving power of the panchromatic film emulsion reached its limits at this tiny scale. While these challenges were overcome, it was decided to initially limit the process to 16mm motion picture film and delay the development of slide film.

Agfacolor Schmalfilm was introduced to the market in mid-1932 (Anon., 1932). Considering how few reels of Agfacolor Schmalfilm have survived to the present, it can be assumed that very little stock was sold and shot at the time. 

In January 1930, a Swiss consortium had been granted the rights to exploit the Keller-Dorian process in Germany, Switzerland, Austria, Czechoslovakia, Poland, Denmark, Holland, Sweden and Norway. Through this consortium, called Opticolor Gesellschaft Glarus, the German Opticolor consortium, lead by Siemens & Halske, came into possession of the licenses. Opticolor was a lenticular film process developed in parallel to Agfacolor Schmalfilm. They pursued the goal of producing a color film production chain for professional application, including the possibility of making lenticular film copies and were thus not in direct competition with Agfacolor Schmalfilm.

In May 1935, Agfa began research work in Wolfen with the aim of developing a lenticular cinema film similar to the Opticolor process. By 1938, when it became clear that the level of illumination required for full-sized cinema projection could not be achieved, this work was discontinued. Meanwhile, the development of Agfa’s lenticular bipack process Pantachrom had progressed to such an extent that it was regarded as having a good chance of solving the problem of color cinematography in Germany. 

With the introduction of Agfa’s revolutionary chromogenic Agfacolor Neu 16mm reversal film, beginning in 1937, the production of the lenticular Agfacolor Schmalfilm was halted – in early 1938, development work of Agfa’s “Berliner Umkehranstalt” laboratory for reversal film was also stopped (Alt, 2011).