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or an object going from one section of the screen to another might jump ahead, appear to be in two places at one time, or completely disappear momentarily if it does not cross at the point of focus.

It is important that the cameraman know this in order that he have the principle subjects, if on the match-line, only at the point of focus. This phenomenon is a product of the characteristics of the camera and must be dealt with; it can not be eliminated. The focusing, therefore, in most cases must be a compromise between the main subject and the subjects on or passing through the match-line. The redeeming feature about the Cinerama camera is that because of the short focal length lenses the depth of field is sufficiently great (even with the lenses wide open) that critical focus is not a serious problem.

Focusing the camera is carried out with a knob located between the "B" and "C" magazines. The figures on the knob are in feet.


Exposure

The Cinerama camera intermittent has a six perforation pulldown and a standard frequency of 26 frames per second. This gives a speed of film through the camera of 146.25 feet per