Laboratory at British Acoustic Films, 1953.
ENGLAND - MAY 06: An engineer works on a laboratory set up to develop magnetic sound in cinema projectors. Film sound tracks began as an optical wave strip beside the picture and the track varied to reproduce the sound. The laboratory appears to be making tests for an alternative process- strips of magnetic tape which will carry the sound signals. Photograph by Walter Nurnberg who transformed industrial photogaphy after WW2 by using film studio lighting techniques. (Photo by Walter Nurnberg/SSPL/Getty Images)