High Speed Motion Picture Photography 



By W. HERRIOTT 



A moition picture camera used in taking 4000 pictures per second 

 is described. Applications of high speed motion picture pho- 

 tography to a variety of problems associated with the design of 

 telephone apparatus are given. The resulting pictures in "slow 

 motion" permit convenient and accurate analysis of space-time 

 relationships of mechanical parts in motion otherwise too rapid to 

 be perceived because of their transient nature. This work has 

 related to the development of relays, switches, clutches, ringers, 

 dials, coin collector mechanisms, contact conditions, materials 

 testing, etc. It has been applied to studies of noise reduction in 

 mechanisms and to research problems associated with the pro- 

 duction of speech by the vocal cords. 



TN 1874 the French astronomer Jenssen pioneered in the use of 

 ••- motion picture photography as a visual aid to the study of a 

 scientific problem. Considerable uncertainty then existed in the 

 value of the earth's distance from the sun and Jenssen employed a 

 camera capable of taking 48 pictures in 70 seconds during the transit 

 of the planet Venus across the sun's disc. He hoped that errors of 

 observation would be substantially less than those inherent in visual 

 observations of this rare and important phenomenon but the results 

 were disappointing due to certain photographic difficulties charac- 

 teristic of the materials at his disposal. He recognized, however, the 

 value of a series of rapidly taken photographs in making evident to 

 the eye changes in the appearance and position of objects which would 

 not otherwise be perceived because of their transient nature. 



E. Muybridge was able to demonstrate in 1878 high speed motion 

 pictures of animals in movement. Jenssen was content to examine 

 his pictures singly under the microscope using the individual photo- 

 graphic images only for record purposes. Muybridge, however, made 

 use of a simple viewing device in which the different pictures secured 

 from a battery of cameras were viewed consecutively when mounted 

 on the inner surface of a rotating cylinder provided with viewing slits. 

 Again we have the application of photography to the discernment of 

 transient movement not otherwise perceptible to the unaided eye. 

 In the following year Muybridge was able to demonstrate the pro- 

 jection of motion pictures onto a viewing screen. 



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