Videotape

Bottom view of VHS videotape cassette with magnetic tape exposed

Videotape is a means of recording images and sound onto magnetic tape as opposed to movie film. In virtually all 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. Video tape is used in both video tape recorders (VTRs or, more common, 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 are becoming more common.

Sadly, an abyss of misinformation has opened up as most consumers believe that DVD is a replacement archival format for videotape even though it is not. No true replacement archive format presently exists that would allow for families to properly archive all of their home-video that has been shot since the late 70's. Mini-DV and Betacam SP are perhaps two of the most logical choices for re-archival of home videotapes, however Betacam Sp requires expensive equipment to run and the tapes are quite large and only hold 94 minutes max per tape, and mini-dv is a fragile format that only holds 63 minutes, an intermediate format one would consider as a middle step on the way to a real archiving format. It appears that videotape is being phased out prior to a real archival format replacing it. Meanwhile, everyday, thousands of consumers may be throwing out their VHS originals with the mistaken belief they have preserved on the DVD format, a format that is easily marred and highly compressed. JVC came up with Digital VHS, a format that could hold 15 hours of video on one two hour tape, but this format just hasn't caught on with the public at large.

History

Open reel

The first practical professional videotape machines were the Quadruplex machines introduced by Ampex in the United States in 1956. Quad employed a transverse (scanning the tape across its width) four-head system on a two-inch (5.08 cm) tape, and linear heads for the soundtrack. The BBC experimented with a high-speed linear videotape system called VERA, but this was ultimately unfeasible. It utilized 1/2 inch (1.27 cm) tape traveling at 200 inches (5.08 m) per second.

Although Quad became the industry standard for 20 years, it had drawbacks such as an inability to freeze pictures, no picture search, and in early machines, a tape could only reliably be played back using the same set of hand-made tape heads, which wore out very quickly. Despite these problems, Quad could produce excellent images. Unfortunately, very few early videotapes still exist. The high cost of early videotapes meant that most broadcasters erased and reused them, and (in the United States) regarded videotape as simply a better and more cost-effective means of time-delaying broadcasts than the previous kinescope technology, which recorded television pictures onto photographic film. It was the four time zones of the continental United States which had made the system very desirable in the first place. However, some early broadcast videotapes have survived, including The Edsel Show, broadcast live in 1957, and 1958's An Evening With Fred Astaire, the oldest color broadcast videotape known to exist (the oldest color videotape is the May 1958 dedication of the WRC-TV studios in Washington, DC). Subsequent videotape systems have used helical scan, where the video heads record diagonal tracks (of complete fields) on to the tape.

The next format to gain widespread usage was the 1" (2.54 cm) Type C format from the middle of the 1970s onwards. It introduced features such as shuttling and still framing, but the sound and picture reproduction attainable on the format were of just slightly less quality to Quad (although 1" Type C's quality was still quite high). However, unlike Quad, 1" Type C machines required much less maintenance, took up less space, and consumed much less electrical power.

The first video cassettes

Then, in 1969, Sony introduced the first widespread video cassette (prior formats had used open reels), the 3/4" (1.905 cm) composite U-matic system, which it later refined to Broadcast Video U-matic or BVU. Sony continued its hold on the professional market with its ever-expanding 1/2" (1.27 cm) component video Betacam family (introduced in 1982), which, in its digital variants, is still among the professional market leaders. Panasonic had some limited success with its MII system, but never could compare to Betacam in terms of market share.

Home VCRs

The first domestic videocassette recorders were launched in the late 1960s (based around U-matic technology), but it was not until Sony's Betamax (1975) and JVC's VHS were launched in the 1970s, that videotape moved into the mass market, resulting in what came to be known as the "videotape format war", which VHS finally won. VHS is still the leading consumer VCR format, since its follow-ups S-VHS and D-VHS never caught up on popularity. It has, however, been displaced in the prerecorded video market by the nonlinear and disc based DVD, although like vinyl records may not become completely obsolete owing to the large number of videocassettes owned by consumers.

The size of a standard VHS tape cassette is 1" x 4" x 7 1/2". Following in the footsteps of standard VHS came other consumer videotape formats such as 8mm video, Hi-8, and digital 8, VHS-C (compact) and S-VHSC.

Going digital

The next step was the digital revolution. Among the first digital video formats Sony's D1, which featured uncompressed digital component recording. Because D1 was extremely expensive, the composite D2 and D3 (by Sony and Panasonic, respectively) were introduced soon after. Ampex introduced the first compressed component recording with its Ampex DCT series in 1992. Panasonic trumped D1 with its D5 format, which was uncompressed as well, but much more affordable.

Consumer videotape options expanded to include digital in 1996 with the debut of the DV standard, which has become widely used both in its native form and in more robust forms such as Sony's DVCAM and Panasonic's DVCPRO as an acquisition and editing format. However, due to concerns by the entertainment industry about the format's lack of copy protection, only the smaller MiniDV cassettes used with camcorders became commonplace, with the full-sized DV cassettes restricted entirely to professional applications.

For camcorders, Sony adapted the Betacam system with its Digital Betacam format, later following it up with the more low-cost Betacam SX and MPEG IMX formats, and the semiprofessional DV-based DVCAM system. 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.

High definition

The introduction of HDTV production necessitated a medium for storing high-resolution video information. In 1997, Sony bumped its Betacam series up to HD with the HDCAM standard and its higher-end cousin HDCAM SR. Panasonic's competing format for cameras was based on DVCPRO and called DVCPRO HD. For VTR and archive use, Panasonic expanded the D5 specification to store compressed HD streams and called it D5 HD.

Camcorders

In camcorders, however, the field has generally been more diverse; early camcorders generally took full-sized VHS or Betamax tapes, but the greatest popularity for some time shared by the 8 mm video format (later replaced by Hi8 and its DV hybrid relative Digital8) and VHS-C (compact) tape. MiniDV is now the most popular format for tape-based consumer camcorders, providing near-broadcast quality video and sophisticated nonlinear editing capability on consumer equipment; however, though intended as a digital successor to VHS, MiniDV VCRs are not widely available outside professional circles. Sony tried to introduce a new camcorder tape with 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. For high definition, the most promising system seems to be HDV, which uses MiniDV media to store a roughly broadcast-quality HDTV data stream.

There has been a trend, largely spearheaded by Hitachi, Panasonic, and Sony, to sell consumer camcorders based on optical discs rather than tape. Most common are DVD recordable camcorders, which are common among point and shoot users due to the ability to take a disc out of the camcorder and drop it directly into a DVD player, much like VHS-C on the analog side. However, professionals consider DVD media to be too inflexible for easy editing, and Sony's ultra-high-end XDCAM system, using Sony's Professional Disc for Data system, is designed for easier editing than DVD media.

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