MOTION-PICTURE PHOTOGRAPHY 



685 



a restless striving, more on the part of directors than cameramen, for grotesque angles, 

 distorted perspective, and a constantly moving camera. In time this urge corrected 

 its own excesses. It is now a generally recognized rule that, while cinematography 

 should not become a traditional or conventional art, anything bizarre that is done 

 with the camera should first of all be dramatically purposeful. Movement of the 

 camera, for example, should not call attention to itself, but to a significant action on 

 the screen. In itself it does not speed up the tempo of a photoplay, and it may detract 



Sunlight 



White flame carbon arc 



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Carbon arc 



Panchromatic carbon arc 



Tungsten 



Mercury vapor 



Wedge spectrograms of light sources. 



from it. The sole purpose of all the elaborate equipment and technique of cine- 

 matography is to tell a story pictorially and dramatically. 



Lighting. — Until 1914 the sun was the only practical illuminant for motion- 

 picture production. Studios, when not open to the elements, were built with glass 

 roofs and walls, cloth diffusing curtains and metal reflectors being used to control the 

 light, after a fashion, as the sun traversed its path or the weather changed. 



When artificial lighting was introduced, it was at first only with the idea of supple- 

 menting daylight, later, of replacing daylight with the same flat, uniform illumination. 

 The lighting units were arc lamps, similar to those used in street lighting, hung over- 

 head and equipped with hoods to reflect the light downward. Mercury-vapor 



