NTSC (National Television System Committee) or
525-30 Video is the composite color video standard used in the United
States. It is used by Video Image for playback purposes, for synchronizing
with motion picture cameras shooting at 29.970 frames-per-second (FPS).
Motion picture film is shot at 29.970 FPS for many television commercials,
and other film productions that may only be seen in a video form, such
as music videos and some episodic television production. NTSC has the following
characteristics:
FRAME RATE - 29.970 frames per second, which equals
59.940 fields per second. Even though 29.970 is the actual frame rate of
NTSC video, we generally refer to the format as 30 frame video.
NUMBER of HORIZONTAL SCAN LINES - 525 lines, which
encompasses 486 lines of image information. The remaining lines are called
the vertical interval, which contain timing information for the video signal,
as well as optional time code information, closed caption information,
videotex, etc.