Maker's Name: 
Bolex Switzerland
Where made: 
22 × 23 × 8 cm

16mm movie camera. 16mm film was made by slicing down the middle of standard 35mm motion picture film stock and gave a good compromise for lighter, cheaper equipment while preserving acceptible image quality for domestic and small-scale professional use. Educational films were usually distributed on 16mm film. The mechanism feeds the film through a gate where it is momentarily held still while the shutter is opened and closed again. This happens about 24 times per second.

Such cameras were used in UQ Physics research to record the displays on cathode ray oscilloscopes used in research on the Earth's ionosphere in the 1950s and 60s. The model J seems to have been a stripped-down model with an external drive suitable for such applications.