Videotape
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 stand-alone tape reel or inside a casing such as a tape cartridge or cassette. Videotape is used in both video tape recorders and, more commonly, videocassette recorders 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 linear 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, 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 audiotape moving at per second. A year later, an improved version using 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, but this was ultimately dropped in favor of quadruplex videotape. VERA used tape on reels traveling at.
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 tape on reels to record five tracks, one each for red, blue, green, synchronization, and audio. The black-and-white system used tape also on reels with two tracks, one for video and one for audio. Both systems ran at with 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 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
Quad
The first commercial professional broadcast quality videotape machines capable of replacing kinescopes were the quadruplex videotape machines introduced by Ampex on April 14, 1956, at the National Association of Broadcasters convention in Chicago. Quad employed a transverse four-head system on a tape and stationary heads for the soundtrack.CBS Television first used the Ampex VRX-1000 Mark IV at its Television City studios in Hollywood on November 30, 1956, to play a delayed broadcast of Douglas Edwards and the News from New York City to the Pacific Time Zone. On January 22, 1957, the NBC Television game show Truth or Consequences, produced in Hollywood, became the first program to be broadcast in all time zones from a prerecorded videotape.
Ampex introduced a color videotape recorder in 1958 in a cross-licensing agreement with RCA, whose engineers had developed it from an Ampex black-and-white recorder. NBC's special, An Evening With Fred Astaire, is the second oldest surviving television network color videotape, and has been restored by the UCLA Film and Television Archive.
On December 7, 1963, instant replay, originally a videotape-based system, was used for the first time during the live transmission of the Army–Navy Game by its inventor, director Tony Verna.
Although Quad became the industry standard for approximately thirty years, it has drawbacks such as an inability to freeze pictures and no picture search. Also, in early machines, a tape could reliably be played back using only the same set of hand-made tape heads, which wore out very quickly. Despite these problems, Quad is capable of producing excellent images. Subsequent videotape systems have used helical scan, where the video heads record diagonal tracks onto the tape.
Many early videotape recordings were not preserved. While much less expensive and more convenient than kinescope, the high cost of 3M Scotch 179 and other early videotapes meant that most broadcasters erased and reused them, and regarded videotape as simply a better and more cost-effective means of time-delaying broadcasts than kinescopes. It was the four time zones of the continental United States which had made the system very desirable in the first place.
Some early broadcast videotapes have survived, including The Edsel Show, broadcast live on October 13, 1957 and An Evening With Fred Astaire which aired on October 18, 1958 and was the oldest color videotape of an entertainment program known to exist until the discovery of the October 8, 1958 episode of the Kraft Music Hall hosted by Milton Berle. The oldest color videotape known to survive is the May 1958 dedication of the WRC-TV studios in Washington, D.C.). In 1976, NBC's 50th-anniversary special included an excerpt from a 1957 color special starring Donald O'Connor; despite some obvious technical problems, the color tape was remarkably good. Some classic television programs recorded on studio videotape have been made available on DVD – among them NBC's Peter Pan with Mary Martin as Peter, several episodes of The Dinah Shore Chevy Show, the final Howdy Doody Show, the television version of Hal Holbrook's one-man show Mark Twain Tonight, and Mikhail Baryshnikov's classic production of the ballet The Nutcracker.
Types C and B
The next format to gain widespread usage was Type C videotape introduced in 1976. This format introduced features such as shuttling, various-speed playback, and still framing. Although Type C's quality was still quite high, the sound and picture reproduction attainable on the format were of slightly lower quality than Quad. However, compared to Quad, Type C machines required much less maintenance, took up less space, and consumed much less electrical power.In Europe, a similar tape format was developed, called Type B videotape. Type B machines use the same 1 inch tape as Type C but they lacked C's shuttle and slow-motion options. The picture quality is slightly better, though. Type B was the broadcast norm in continental Europe for most of the 1980s.
Professional cassette formats
A videocassette is a case containing videotape. In 1969, Sony introduced a prototype for the first widespread video cassette, the composite U-matic system, which Sony introduced commercially in September 1971 after working out industry standards with other manufacturers. Sony later refined it to Broadcast Video U-matic. Sony continued its hold on the professional market with its ever-expanding component video Betacam family introduced in 1982. This tape form factor would go on to be used for leading professional digital video formats. Panasonic had some limited success with its MII system, but never could compare to Betacam in terms of market share.The next step was the digital revolution. Sony's D-1 was introduced in 1986 and featured uncompressed digital component recording. Because D-1 was extremely expensive, the composite D-2 and D-3 were introduced soon after. Ampex introduced the first compressed component recording with its DCT series in 1992. Panasonic's D-5 format was introduced in 1994. Like D-1, it is uncompressed, but much more affordable.
The DV standard, which debuted in 1995, and was widely used both in its native form as MiniDV and in more robust professional variants.
In digital camcorders, Sony adapted the Betacam system with its Digital Betacam format in 1993, and in 1996 following it up with the cheaper Betacam SX and the 2000 MPEG IMX format, The semiprofessional DV-based DVCAM system was introduced in 1996. Panasonic used its DV variant DVCPRO for all professional cameras, with the higher-end format DVCPRO50 being a direct descendant. JVC developed the competing D9/Digital-S format, which compresses video data in a way similar to DVCPRO but uses a cassette similar to S-VHS media. Many helical scan cassette formats such as VHS and Betacam use a head drum with heads that use azimuth recording, in which the heads in the head drum have a gap that is tilted at an angle, and opposing heads have their gaps tilted so as to oppose each other.