From Wikipedia, the free encyclopedia
Videotape is a means of recording images and sound on to magnetic tape as opposed to movie film. Videotapes are also used for storing scientific or medical data, such as the data produced by an electrocardiogram. In most cases, a helical scan video head rotates against the moving tape to record the data in two dimensions, because video signals have a very high bandwidth, and static heads would require extremely high tape speeds. Videotape is used in both video tape recorders (VTRs) or, more commonly, video cassette recorders (VCRs) and video cameras. Tape is a linear method of storing information and, since nearly all video recordings made nowadays are digital, it is expected to gradually lose importance as non-linear/random-access methods of storing digital video data become more common.
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. Developed 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 quarter-inch (0.6 cm) audio tape moving at 360 inches (9.1 m) per second.[1][2] A year later, an improved version, using one-inch (2.6 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.[3] Bing Crosby Enterprises hoped to have a commercial version available in 1954, but none came forth.[4] BCE demonstrated a color model in February 1955, using a longitudinal recording on half-inch (1.3 cm) tape, essentially similar to what RCA had demonstrated in 1953 (see below). CBS, RCA's competitor, was about to order BCE machines when Ampex introduced the superior Quadruplex system (see below).[5]
RCA demonstrated the magnetic tape recording of both black-and-white and color programs at its Princeton laboratories on December 1, 1953.[6][7] The high-speed longitudinal tape system, called Simplex, in development since 1951, could record and play back only a few minutes of a program. The color system used half-inch (1.3 cm) tape to record five tracks — one each for red, blue, green, synchronization, and audio. The black-and-white system used quarter-inch (0.6 cm) tape with two tracks, one for picture and one for sound. Both systems ran at 360 inches (9.1 m) per second.[8] RCA-owned NBC first used it on the The Jonathan Winters Show on October 23, 1956, when a pre-recorded song sequence by Dorothy Collins in color was included in the otherwise live program.[9][10] The BBC experimented from 1952 to 1958 with a high-speed linear videotape system called VERA, but this was ultimately unfeasible. It used half-inch (1.27 cm) tape traveling at 200 inches (5.08 m) per second.
Home video
VCRs
The first consumer videocassette recorders were launched in 1971 (based around U-matic technology), but it was not until Sony's Betamax (1975) and JVC's VHS (1976) were launched that videotape moved into the mass market, resulting in what came to be known as the "videotape format war", which VHS ultimately won. Videocassettes finally made it possible for consumers to buy or rent a complete film and watch it at home whenever they wished, rather than simply catching it at a movie theatre or having to wait until it was telecast. It also made it possible for a VCR owner to record films and other television programs "off the air". This caused an enormous change in viewing practices, as one no longer had to wait for a repeat of a program that had been missed. The shift to home viewing also changed the movie industry's revenue streams, because home renting created an additional "window" in which a film could make money. In some cases, films that did only modestly in their theater releases went on to have strong performance in the rental market (e.g., cult films).
VHS has become the leading consumer VCR format after the "war", though its follow-ups S-VHS, W-VHS and D-VHS never caught up in popularity. In the late 1990s in the prerecorded video market, VHS began to be displaced by DVD. The DVD format had several advantages over VHS tape. A DVD disk is much better able to take repeated viewings than VHS tape, which can crack or break, which makes DVDs a better format from a rental store's perspective. As well, whereas a VHS tape can be erased if it is exposed to a magnetic field (such as by being left near a speaker), DVDs are not affected by magnetic fields. Even though DVDs do not have the problems of tapes, such as breakage of the tape or the cassette mechanism, DVDs can still be damaged by scratches. Another factor for movie rental stores is that DVDs are smaller and take less space to store. DVDs offer a number of advantages for the viewer: DVDs can support both standard 4x3 and widescreen 16x9 screen aspect ratios and DVDs can provide twice the video resolution than VHS. As well, a viewer who wants to skip ahead to the end of a movie can do so much quicker with a DVD than with a VHS tape (that has to be rewound). DVDs can have interactive menus, multiple language tracks, audio commentaries, Closed Captioning and subtitling (with the option of turning the subtitles on or off, or selecting subtitles in several languages). Moreover, a DVD can be played on a computer.
Due to these advantages, by the mid-2000s, DVDs were the dominant form of prerecorded video movies in both the rental film and new movie markets. In the late 1990s and early 2000s, though, consumers continued to use VCRs to record over-the-air TV shows, because consumers could not make home recordings onto DVD disks. This last barrier to DVD domination was broken in the late 2000s, with the advent of inexpensive DVD recorders and digital video recorders (DVR). DVR devices, which record shows onto a hard disk, can be purchased from electronics stores or rented from cable or satellite TV providers. Despite the mainstream dominance of DVD, VHS continues to have a role. The conversion to DVD has led to the marketplace being flooded with used VHS films, which are available at pawnshops and second-hand stores, typically for a cheaper price than the equivalent film on a used DVD. As well, due to the large number of VHS players in schools and libraries, VHS tapes are still produced for the educational market.
CAMCODERS
Early consumer camcorders used full-size VHS or Betamax cassettes. Later models switched to more compact formats, designed explicitly for camcorder use, like VHS-C and Video8. VHS-C was a downsized version of VHS, using the same recording method and the same tape, but in a smaller cassette. It was possible to play VHS-C tapes in a regular VHS tape recorder by using an adaptor. After Super VHS had appeared, a corresponding compact version, Super VHS-C, was released as well. Video8 was an indirect descendant of Betamax, using narrower tape and a smaller cassette. Because of its intricate U-shaped tape loading and narrower tape, it was not possible to develop an adapter from Video8 to Betamax. Video8 was later replaced with Hi8, which provided better resolution and high-quality sound recording, and was similar to Super VHS-C.
The first consumer digital video recording format, introduced in 1995, used a smaller Digital Video Cassette (DVC).[17] The format was later renamed MiniDV to reflect the DV encoding scheme, but the tapes still carry "DVC" mark. Some later formats like DVC Pro from Panasonic reflect the original name. The DVC/MiniDV format provided near-broadcast quality video and sophisticated nonlinear editing capability on consumer equipment. In 1999 Sony backported the DV recording scheme to 8-mm systems, creating Digital8. By using the same cassettes as Hi8, many Digital8 camcorders were able to play analog Video8/Hi8 recordings, preserving compatibility with already recorded analog tapes. As of 2008, Digital8 camcorders have been removed from the equipment offered by Sony.
Sony introduced another camcorder cassette format called MicroMV, but consumer interest was low due to the proprietary nature of the format and limited support for anything but low-end Windows video editors, and Sony shipped the last MicroMV unit in 2005. In the late 2000s, MiniDV and its high-definition cousin, HDV, are the two most popular consumer tape-based formats. The formats use different encoding methods, but the same cassette type. Since 2001, when MicroMV was presented, no new tape form factors have been introduced.
Future of tape
The latest trend in consumer camcorders shows the switch from tape-based to tapeless solutions, like built-in hard disk drives, optical discs and solid-state memory. In particular, Canon have not introduced a completely new HDV consumer camcorder for a third year in a row, confining itself to minor modifications to the 2007 model. Sony and Panasonic have removed their consumer tape-based camcorders from the North American market completely. In professional video recording settings, such as broadcast television, videotape was still heavily used in the mid- to late 2000s, but tapeless formats like DVCPRO P2, XDCAM and AVCHD, are gaining broader acceptance.
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