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The entire wiki reimagined as a visual magazine with video discovery · Watch your interests come alive
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Phonofilm
Videos
Phonofilm is an optical variable density sound-on-film system developed by inventors Lee de Forest and Theodore Case in the early 1920s.
A piece of early sound equipment of the De Forest Phonofilms Corporation
A piece of early sound equipment of the De Forest Phonofilms Corporation
Charles Ward, sound engineer, fitting the sound-head to the projector of the De Forest Phonofilms' sound film system
Charles Ward, sound engineer, fitting the sound-head to the projector of the De Forest Phonofilms' sound film system
Newspaper ad for Phonofilm shorts shown at the Strand Theatre in Biloxi, Mississippi (Biloxi Daily Herald, December 5, 1925)
Newspaper ad for Phonofilm shorts shown at the Strand Theatre in Biloxi, Mississippi (Biloxi Daily Herald, December 5, 1925)
Advertisement for the American film Love's Old Sweet Song (1923) with Louis Wolheim, Helen Lowell, Donald Gallaher, and Helen Weir
Advertisement for the American film Love's Old Sweet Song (1923) with Louis Wolheim, Helen Lowell, Donald Gallaher, and Helen Weir
Optical sound
Videos
Optical sound is a means of storing sound recordings on transparent film. Originally developed for military purposes, the technology first saw widespread use in the 1920s as a sound-on-film format for
Edge of a 35-mm film print showing four types of soundtrack. The stereo optical sound strip is located on the right, with waveforms for left and right
Edge of a 35-mm film print showing four types of soundtrack. The stereo optical sound strip is located on the right, with waveforms for left and right channels. To the far left is the SDDS digital track (blue area to the left of the sprocket holes), then the Dolby Digital (grey area between the sprocket holes labeled with the Dolby "Double-D" logo in the middle), and to the right of the analog optical sound is the DTS time code (the dashed line to the far right.)
A transparent program disc imprinted with concentric optical sound tracks, used for the Optigan musical organ
A transparent program disc imprinted with concentric optical sound tracks, used for the Optigan musical organ
Example of a variable-area sound track on the right side of the frames on this strip of 16mm film. The width of the white area is proportional to the
Example of a variable-area sound track on the right side of the frames on this strip of 16mm film. The width of the white area is proportional to the amplitude of the audio signal at each instant.