frame frequency[′frām ‚frē·kwən·sē]
(1) The rate of succession of the film frames during motion-picture filming or projection; the same as the filming or projection speed. The standard filming and projection speed is 24 frames per sec; 8-mm and 16-mm films are sometimes exposed and projected at a speed of 16 frames per sec. If filming is done at a speed higher or lower than the projection speed, the action photographed will be seen as retarded or speeded up, respectively, during projection. The two effects are widely used in all types of motion pictures.
(2) The rate at which complete frames change on the screen of a television receiver. The frame frequency adopted as a television standard in the USSR is 25 frames per sec.