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HANDBOOK OF PHOTOGRAPHY 



hofer lines. As the spectral range of the film was extended, it became common 

 practice to bring the blue G and red C lines to the focal plane. Other correction 

 requirements have likewise become more critical. 



The so-called "zoom" lens is peculiar to motion-picture photography. It is used 

 to give the effect of a moving shot with a stationary camera, by varying the focal 

 length and the magnification during the shot. This is accomplished by rotating a 

 crank coupled with a dial indicating the focal length and magnification. In the Cooke 

 type of zoom lens the range of focal lengths is 40 to 120 mm. at apertures of //8 and 

 //5.6. At larger apertures the range is reduced. 



Motion-picture cameras are usually mounted on rigid tripods, but for moving shots 

 a variety of types of "dollies" are employed. One form, known by the trade name 

 Rotambulator, is shown in Fig. 29 with camera and operator in place. The principal 



Fig. 29. — Camera dolly (rotambulator). 



requisites of a good dolly are ease, speed, and quietness of movement. The type 

 illustrated may be fixed in position by lifting the platform off the wheels, the platform 

 may be rotated for "panning," and the camera table may be moved horizontally and 

 tilted; convenient controls are provided for all these operations. 



For three-dimensional movement over wide ranges, camera cranes are utilized. 

 Some of these are large, elaborate structures carrying two or three men in addition 

 to the camera, with equivalent counterweighting to ensure fast and safe operation. 



A common pattern of shooting, derived from experience, is to start with a long or 

 full shot, cut to a medium shot, and then to a close-up, in this way establishing the 

 scene and the characters and proceeding naturally to an intimate vantage point. Or, 

 depending on the script, the opposite order may be appropriate in some cases. 



The angles and inclusion of field in motion-picture photography vary so widely 

 that all one can say is that anything is possible and almost everything has been tried, 

 sometimes with results scarcely repaying the effort. A number of years ago there was 



