Swedish Inventor Sven Berglund's Little-Known Achievements in the Development of Motion Picture Optical Sound Recording

On June 26, 2009, archivists at the Deutsches Film Museum (DFM) in Frankfurt found a lonely reel of cellulose nitrate base optical sound film. Labeled "Berglund VI Tonaufnahmen 1922," the 750-foot reel of 35mm nitrate film was in a can of film from the Filzinger Archive. The seemingly insignificant find turned out to be a rare artifact of Swedish inventor Sven Berglund and his colleague Wolfgang Filzinger from the early years of sound motion picture experimentation. Though Berglund is not a familiar name to most researchers and archivists, the documentation of his accomplishments confirms that synchronized sound motion picture production and exhibition was feasible in 1921. The recovery of this reel, which was lent by the DFM to the Swedish Film Institute, provided tangible evidence for the effectiveness of Berglund's optical sound recorder.

At the beginning of the 1920s, technology was rapidly evolving in the motion picture industry. Though sound for motion pictures was scorned by a good portion of the production and exhibition community, a small but dedicated group of technologists persevered and forever changed an art form and commercial product. The key contributors in the history of motion picture sound—Lee de Forest, Theodore Case, E. I. Sponable, E. C. Wente, (Axel) Peterson and (Arnold) Poulsen, Eugene Lauste, and the team at Tri-Ergon—are well known to scholars, archivists, and researchers. However, Sven Berglund, a Swedish engineer, is not a name that many would immediately associate with the development of optical sound technology.

Berglund was born on July 20, 1881, in Stockholm. His father, Archadius, was a military engineer who edited the second edition of The Book of Inventions (1898-1907), a worldwide compendium of registered current inventions. Berglund followed his father's scientific path by attending the Technical University of Berlin-Charlottenburg in 1901. Working in the photographic industry in Berlin after graduation, Berglund experimented with optically recording acoustical sound waves onto photographic plates. ¹

By 1911, Berglund had perfected a system to record optical sound onto a continuous piece of nonperfed 35mm film. His original invention can be found in the Deutsches Museum in Munich, Germany. Working with Goerzen Optical Co., a German manufacturer of motion picture cameras and lenses, he attracted investors interested in developing a system for synchronizing sound for motion pictures. The venture, called Fotoaerofon, was one of a number of companies Berglund would form to raise capital for his motion picture sound system. During the early years of motion picture development, patents and licenses controlled the manufacturing of cameras and projectors, creating profitable monopolies for their owners. Technical innovators also understood that bringing a viable sound system to motion pictures would be another opportunity to cash in on the fledgling industry. Thus Berglund once said that "an inventor devotes at least as much time to raise money for his research, as he spends on the research work." ²

World War I interrupted Berglund's work in Germany, and he returned home to Stockholm. When it was evident that the war would rage on for years, Berglund made a daring trip back to Goerzen in Berlin to pack up his equipment and ship it to Sweden to continue his research.

Figure 1.

Sven Berglund in his laboratory at Lidingö. Originally published in the magazine The Film (1919).

The cornerstone of Berglund's acoustical optical recording system was the ability to have sound waves modulate light so that the sound energy could be recorded photographically on black-and-white film. This is essentially the same technology that is used for motion picture optical sound tracks today. Converting sound waves to modulating light was not his original idea—Alexander Graham Bell and Charles Sumner Tainter pioneered this work in the 1880s with their invention of the photophone; however, by harnessing this phenomenon, Berglund could record sounds farther away from the recording funnel. This advantage is gained by the fact that light has no mass. Berglund's system therefore required much less acoustical energy than the traditional stylus-cutting method employed on...