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Navy Electronic Shutter Analyzer
BY W. R. ERASER
U. S. NAVAL PHOTOGRAPHIC CENTER, ANACOSTIA 20, D. C.
Summary — A new electronic shutter analyzer employing a two-gun cathode-ray oscilloscope with two phototubes has been developed by the Navy. This device is designed to permit the rapid analysis and solution of numerous problems commonly encountered in photography including: (1) shutter operation and efficiency; (2) shutter-flash synchronization; (3) shutter-solenoid delay; (4) flash-gun-switch, solenoid-shutter delay; (5) internal-shutter-switch contact time; (6) switch or electrical contact efficiency; (7) diaphragm calibration; (8) duration and intensity of light as emitted by flashbulbs and some gaseous discharge tubes.
INTRODUCTION
THE FUNDAMENTAL PROBLEM in everyday photography is to make sure that the correct amount of light is permitted to strike the unexposed negative in the camera. Since a film of infinite latitude has not as yet made its appearance, and narrow latitude color film has, it becomes increasingly necessary to measure accurately the effective exposure time.
The importance of "getting that picture," whether it be during a battle or in a research laboratory, warranted development of a testing device that would rapidly and graphically furnish the information necessary to calibrate the cameras properly. The problem was to develop an equipment which could be operated by a naval photographer and which would be useful in the solution of a majority of the photographic problems. The Research and Development Department of the United States Naval Photographic Center, under the general supervision of the Bureau of Aeronautics, conducted a survey of camera-shutter testing problems as encountered at various Naval research laboratories, test stations, and the like.
On the basis of this survey, it was decided to utilize the visual type of presentation on a cathode-ray oscilloscope as outlined in the American War Standard Specification Z52. 63-1946. However, Specification Z52. 63-1946 covering a "Method of Determining Performance Characteristics of Between-the-Lens Shutters used in StillPicture Cameras" did not permit analysis of shutter-flash sjTichronism
* Presented April 8, 1949, at the SMPE Convention in New York. 256 SEPTEMBER, 1949 JOURNAL OF THE SMPE VOLUME 53