Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. The tape can come in a stand-alone tape reel or inside a casing such as a tape cartridge or cassette. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocassette recorders (VCRs) and camcorders. Videotapes have also been used for storing scientific or medical data, such as the data produced by an electrocardiogram. Because video signals have a very high bandwidth, and stationary heads would require extremely high tape speeds, in most cases, a helical-scan video head rotates against the moving tape to record the data in two dimensions. Tape is a sequential access method of storing information and thus imposes delays to access a portion of the tape that is not already against the heads. The early 2000s saw the introduction and rise to prominence of high-quality random-access video recording media such as hard disks and flash memory. Since then, videotape has been increasingly relegated to archival and similar uses.
Early formats The electronics division of entertainer Bing Crosby's production company, Bing Crosby Enterprises (BCE), gave the world's first demonstration of a videotape recording in Los Angeles on November 11, 1951. In development by John T. Mullin and Wayne R. Johnson since 1950, the device gave what were described as "blurred and indistinct" images using a modified Ampex 200 tape recorder and standard one-quarter-inch (0.64 cm) audiotape moving at 360 inches (9.1 m) per second. A year later, an improved version using one-inch (2.5 cm) magnetic tape was shown to the press, who reportedly expressed amazement at the quality of the images, although they had a "persistent grainy quality that looked like a worn motion picture." Overall, the picture quality was still considered inferior to the best kinescope recordings on film. Bing Crosby Enterprises hoped to have a commercial version available in 1954, but none came forth. The BBC experimented from 1952 to 1958 with a high-speed linear videotape system called Vision Electronic Recording Apparatus (VERA), but this was ultimately dropped in favor of quadruplex videotape. VERA used one-half-inch (1.3 cm) tape on 20-inch (51 cm) reels traveling at 200 inches per second (5.1 m/s). RCA demonstrated the magnetic tape recording of both black-and-white and color television programs at its Princeton laboratories on December 1, 1953. The high-speed longitudinal tape system, called Simplex, in development since 1951, could record and play back only a few minutes of a television program. The color system used one-half-inch (1.3 cm) tape on 10+1⁄2-inch (270 mm) reels to record five tracks, one each for red, blue, green, synchronization, and audio. The black-and-white system used one-quarter-inch (0.64 cm) tape also on 10+1⁄2-inch (270 mm) reels with two tracks, one for video and one for audio. Both systems ran at 360 inches per second (9.1 m/s) with 2,500 feet (760 m) per reel yielding an 83-second capacity. RCA-owned NBC first used it on The Jonathan Winters Show on October 23, 1956, when a prerecorded song sequence by Dorothy Collins in color was included in the otherwise live television program. In 1953, Norikazu Sawazaki developed a prototype helical scan videotape recorder. BCE demonstrated a color system in February 1955 using a longitudinal recording on one-half-inch (one-point-three-centimetre) tape. CBS, RCA's competitor, was about to order BCE machines when Ampex introduced the superior Quadruplex system. BCE was acquired by 3M Company in 1956. In 1959, Toshiba released the first commercial helical scan videotape recorder.
Broadcast video
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