The Video Home System, better known by its abbreviation VHS, is a recording and playing standard developed by Victor Company of Japan, Limited (JVC) and launched in Europe/Asia in September 1976 (U.S. launch was June 1977), with The Young Teacher being the first movie to be released and A History of Violence, released on home video in 2006, being the last in the North American market. By the 1990s, VHS became a standard format for consumer recording and viewing, after competing in a fierce format war with Sony Corporation's Betamax and, to a much lesser extent, Philips' Video 2000, MCA's Laserdisc and RCA's Capacitance Electronic Disc.
VHS initially offered a longer playing time than the Betamax system, and it also had the advantage of a far less complex tape transport mechanism. Although VHS and Betamax were competing formats, several of VHS's critical technologies are licensed from Sony. Early VHS machines could rewind and fast forward the tape considerably faster than a Betamax VCR because they unthreaded the tape from the playback heads before commencing any high-speed winding. Most newer VHS machines do not perform this unthreading step, as head-tape contact is no longer an impediment to fast winding, owing to improved engineering.
DVDs rentals surpassed VHS rentals in the US in 2003, surprising some industry officials. By 2006, most major film studios stopped releasing new movie titles in VHS format, opting for DVD-only releases. Many leading retailers have stopped selling pre-recorded movies on VHS, although VHS prerecorded cassettes are still popular with many collectors, mainly because there are thousands of titles that are still unavailable on DVD or other newer formats.
The recording medium is a ½ inch (12.7 mm) wide magnetic tape wound between two spools, allowing it to be slowly passed over the various playback and recording heads of the video cassette recorder. The tape speed is 3.335 cm/s for NTSC, 2.339 cm/s for PAL. A cassette holds a maximum of about 430 m of tape at the lowest acceptable tape thickness, giving a maximum playing time of about 3.5 hours for NTSC and 5 hours for PAL at "standard" (SP) quality. Other speeds include LP and EP/SLP which double and triple the recording time, for NTSC regions. These speed reductions cause a slight reduction in video quality (from 250 lines to 230 lines horizontal); also, tapes recorded at the lower speed often exhibit poor playback performance on recorders other than the one they were produced on. Because of this, commercial prerecorded tapes were almost always recorded in SP mode.
As with almost all cassette-based videotape systems, VHS machines pull the tape from the cassette shell and wrap it around the head drum. VHS machines, in contrast to Betamax and Beta's predecessor U-matic, use an M-loading system, also known as M-lacing, where the tape is drawn out by two threading posts and wrapped around the head drum (and other tape transport components) in a shape roughly approximating the letter M.
VHS tapes have approximately 3 MHz of video bandwidth, which is achieved at a relatively low tape speed by the use of helical scan recording of a frequency modulated luminance (black and white) signal, with a down-converted "color under" chroma (color) signal recorded directly at the baseband. Because VHS is an analog system, VHS tapes represent video as a continuous stream of waves, in a manner similar to analog TV broadcasts. The waveform per scanline can reach about 160 waves at max, and contains 525 scanlines in NTSC (486 visible), or 625 lines in PAL (576 visible). In modern-day digital terminology, VHS is roughly equivalent to 320 pixels of horizontal resolution with a signal-to-noise ratio of the image at 43 dB.
JVC would counter 1985's SuperBeta with VHS HQ, or High Quality. The frequency modulation of the VHS luminance signal is limited to 3.1 megahertz which makes higher resolutions impossible, but an HQ branded deck includes luminance noise reduction, chroma noise reduction, white clip extension, and improved sharpness circuitry. The effect was to increase the apparent horizontal resolution of a VHS recording from 240 to 250 lines. The major VHS OEMs resisted HQ due to cost concerns, eventually resulting in JVC reducing the requirements for the HQ brand to white clip extension plus one other improvement.
In 1987 JVC introduced the new format called Super VHS which extended the bandwidth to over 5 megahertz, yielding 420 lines horizontal (equivalent to 560x486 in digital terminology). For comparison DVD is 500 lines horizonal. The chroma resolution remained the same at approximately 0.6 megahertz bandwidth or 30 lines horizontal, as was common across analog tape standards from Umatic to VHS to ED Betamax. Even a live NTSC broadcast is limited to 120 chroma lines maximum. (For comparison DVD is 240 chroma horizontal.)
Around 1985, HiFi VCRs emerged, adding higher-quality stereo audio tracks (20 Hz to 20 kHz with more than 70 dB S/N ratio) which are read and written by heads located on the same spinning drum that carries the video heads with frequency modulation. These audio tracks take advantage of depth multiplexing: since they use lower frequencies than the video, their magnetization signals penetrate deeper into the tape. When the video signal is written by the following video head, it erases and overwrites the audio signal at the surface of the tape, but leaves the deeper portion of the signal undisturbed. (PAL versions of Betamax use this same technique.) Some high-end VHS VCRs offered manual level control, which made the VHS HiFi format much more useful for high-quality audio-only recording. The excellent sound quality of HiFi VHS has gained it some popularity as an audio format in certain applications; in particular, ordinary home HiFi VCRs are sometimes used by home recording enthusiasts as a handy and inexpensive medium for making high-quality stereo mixdowns and master recordings from multitrack audio tape. However, because separate heads are used to record HiFi audio, advanced editing functions such as audio-only or video-only dubbing are impossible.
The ADAT format provides the ability to record digital audio using S-VHS media.
The other improved standard, called Digital-VHS (D-VHS), records digital high definition video onto a VHS form factor tape. D-VHS can record up to 4 hours of ATSC Digital Television in 720p or 1080i formats using the fastest record mode (equivalent to VHS-SP), and up to 40 hours of standard definition video at slower speeds.
Sony Betamax was unable to shrink that form any further, so instead they developed Video8/Hi8 which was in direct competition with the VHS-C/S-VHS-C format throughout the 80s, 90s, and 2000s. Ultimately neither format "won" and both continue to be sold in the low-end market (examples: JVC SXM38 and Sony TRV138). Super VHS-C camera recordings can be played back in standard VHS VCRs with SVHS-ET technology.
Since the 1990s, dual- and multi-standard VHS machines have become more and more common. These can handle VHS tapes of more than one standard. For example, regular VHS machines sold in Australia and Europe nowadays can typically handle PAL, MESECAM for record and playback, plus NTSC for playback only. Dedicated multistandard machines can usually handle all standards listed, some high end model can even convert a tape from one standard to another by using a built-in standards converter.
S-VHS only exists in PAL/625/25 and NTSC/525/30. S-VHS machines sold in SECAM markets record internally in PAL, and convert to/from SECAM during record/playback, respectively. Likewise, S-VHS machines for the Brazilian market record in NTSC and convert to/from PAL-M.
A small number of VHS decks are able to decode closed captions on pre-recorded video cassettes. A smaller number still are able, additionally, to record subtitles transmitted with world standard teletext signals (on pre-digital services), simultaneously with the associated program.
In order to avoid confusion, manufacturers indicate the playing time in minutes that can be expected for the market the tape is sold in. It is perfectly possible to record and play back a blank T-XXX tape in a PAL machine or a blank E-XXX tape in an NTSC machine, but the resulting playing time will be different from that indicated. SP is Standard Play and LP is Long Play at 1/2 speed for both NTSC and PAL regions. EP/SLP designates Extended Play/Super Long Play at 1/3rd speed for NTSC regions. (PAL does not have an EP speed.)
|Tape Label||Tape Length||Rec. Time (NTSC)||Rec. Time (PAL)|
|DF480 (T-240 equiv)||1624||495.0||4:00||8:00||12:00||5:40||11:20|
As mentioned, VHS was the winner of a protracted and somewhat bitter format war during the late 1970s and early 1980s against Sony's Betamax format.
Betamax was widely perceived at the time as the better format, as it offered a slightly higher horizontal resolution (250 lines vs. 240 lines in PAL & NTSC), lower video noise, and less luma-chroma crosstalk than VHS, and was marketed as providing pictures superior to VHS's, however the introduction of B-II speed (2-hour mode) to compete with VHS's 2-hour Standard Play mode, reduced Betamax's horizontal resolution to 240 lines. The extension of VHS to VHS HQ produced 250 lines, so that overall a Betamax/VHS user could expect virtually identical luminance and chrominance resolution (~30 lines across), wherein the actual picture performance depended on other factors, including the condition and quality of the videotape, and the specific video recorder machine model.
Betamax held an early lead in the format war — but by 1981, U.S. Betamax sales had sunk to only 25% of all sales. VHS was gaining market share due to its longer tape time (in 1981, 9 hours maximum, compared to just 4 hours for Betamax in USA) and JVC's less strict licensing program. The longer tape time is sometimes cited as the defining factor in the format war, allowing consumers to record entire programs unattended (recording time between VHS and Betamax were similar in areas where VHS entered the market several years after introduction, such as the UK in 1978). Sony ultimately conceded the fight in 1988, bringing out a line of VHS VCRs of its own.
The format war and the "marketing over technology" claims have taken on a life of their own, and continue to be used as analogies in battles within the computer industry, including Apple vs. IBM, Macintosh vs. PC, and HD DVD vs. Blu-ray Disc. Other formats such as 8 mm video cassettes and MiniDV have emerged since the post-battle era, although these formats did little to erase VHS dominance in the home.
Both VHS and Betamax manufacturers created professional video formats built around the same cassette shells. The professional derivatives of VHS were M and then MII whereas the professional derivative of Betamax was Betacam which has gone on to spawn digital variants. In a complete reversal of the domestic VHS-Betamax battle, in the professional arena the Beta format has been hugely successful, and the VHS derived formats became obsolete. Occasionally this causes some confusion, in that people believe that Betacam is a professional studio version of Betamax. In reality Betacam is only superficially similar. Although the tapes used may look the same,and the first generation Betacam tapes could be used for recording in Betamax machines, in Betacam they are run at a much higher linear speed, and the recording system is completely different. The same applied to the VHS based-professional formats.
Signs of VHS's decline come from two directions. First, electronic equipment manufacturers are downsizing their VHS recorder production lines. Both department and electronic "boutique" stores are also cutting down on the variety of VHS recorders they carry in-stock — especially the higher-end systems such as S-VHS recorders. In most stores, DVD players are now cheaper than VHS players.
Second, video content in VHS format is also slowly disappearing. The popularity of VHS in both for-sale and rental stores has fallen. Most retail stores have stopped selling new VHS movies alongside DVD versions.
Virtually only VHS/DVD combination units are available at retail stores in North America, but stand-alone 4 and 6 head VCRs are still manufactured by LG and available for sale in Australia. The last standalone JVC VHS unit was reportedly produced in 2007. The final major Hollywood motion picture released on VHS was David Cronenberg's A History of Violence.
Many TV stations choose to continue to use the VHS format for archiving programs and footage over other formats because of the tapes wide acceptance and availability at a lower cost than many other formats. Because the VHS format is still widely accepted for personal use many stations choose to use it to easily copy and distribute tapes.
Although VHS is slowly declining, this dilemma does bring along with it opportunities, such as media conversion services, dual-deck and DVD/VCR combination systems, and even a lucrative re-sell market on auction and second-hand equipment sites.
Consumers still retain the technology as well. The Washington Post has noted that as of 2005, 94.5 million Americans still owned VHS format VCRs. In spite of the decline of pre-recorded VHS sales, blank, recordable VHS cassettes remain the most popular means of recording live television programming in households around the world.
Despite DVD's better quality (500 lines versus 250 lines horizontal resolution), VHS is still widely used in home recording of television programs, due to the large installed base and the lower cost of VHS recorders and tape. The commercial success of DVD recording and re-writing has been hindered by a number of factors including:
Hard disk-based systems include TiVo as well as other digital video recorder (DVR) offerings. These types of systems provide users with virtually a no-maintenance solution for capturing video content. VHS and other cartridge solutions require physical handling of the media, as well as upkeep duties such as cleaning of the heads. Unlike both cartridge-based and optical disc-based systems, hard disk-based systems allow for many hours of recording without physical maintenance. For example, a 120 GB system recording at an extended recording rate (XP) of 9,800 kbit/s MPEG-2 can record over 25 hours of video content. Just like VHS, the latest optical disc technologies must still rely on tangibles, such as blank discs.
PC-based media centers are also becoming popular in homes. PCs can serve the same features as a DVR set-top box, but also add a usable operating environment for other tasks such as electronic mail and surfing the Internet. A media center may be the better solution for the technical-savvy consumer who is looking for a system he can regularly upgrade, such as disk capacity and software.