Short length of Photophone film

Short length of film made by Radio Corporation of America "Photophone" process (encased in glass, plus modern copy print).

RCA Photophone was an optical sound, "variable-area" film system, in which the modulated area (width) corresponded to the waveform of the audio signal. From 1927, cinemas could purchase a bolt-on sound head to convert silent projectors into sound projectors. A service of post-recording of musical scores for silent films was available to any company who would provide a silent print for the preparation of the score. The first feature film shot in Photophone was 'The Perfect Crime' in 1928.