34
2-3 pulldown
Motion picture film is intended for display at 24 frames per second. Many television programs, including a large number of prime-time programs, historically originated on film at this rate (or at 1000/1001 of 24 Hz, that is, 23.976 Hz). This chapter discusses the conversion of film to frame rates higher than 24 Hz.
Except for certain very unusual film formats, motion picture film runs vertically through the camera and the projector. Be wary of anyone who presents a diagram like Figure 34.1 but rotated 90°.
Film has historically been transferred to 29.97 frame per second video using a technique called 2-3 pull-down, whereby successive film frames are scanned first twice then three times to produce five video fields. The process ...
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