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Pioneer's LaserDisc Logo

The laserdisc (LD) was the first commercial optical disc storage medium, and was used primarily for the presentation of movies.

During its development, the format was referred to as the Reflective Optical Videodisc System before MCA, who owned the patent on the technology, re-named the format Disco-Vision in 1969. By the time the format was brought to market in 1978, the hyphen had been removed from the format name, and DiscoVision without the hyphen became the official format name. Sales of DiscoVision players & discs began on December 15, 1978 starting in Atlanta, Georgia. MCA owned the rights to the largest catalog of films in the world during this time, and they directly manufactured and distributed the discs of their movies under the "MCA DiscoVision" label. Pioneer Electronics, who entered the market almost at exactly the time DiscoVision titles were going on sale in 1978, began manufacturing players and printing discs under the name laser videodisc. By 1981, Laserdisc (first in CamelCase as LaserDisc, later without the inter caps) had become the common name for the format, and the Discovision label disappeared, simply becoming MCA or (later) MCA-Universal Laserdisc.

MCA also manufactured discs for other companies, including Paramount, Disney and Warner Brothers. Some of them added their own names onto the disc-jacket in order to signify the movie was not owned by MCA. When MCA folded into Universal several years later, Universal began re-issuing many of the early DiscoVision titles as Universal discs. The DiscoVision versions had largely been available only in pan and scan and had often utilized poor transfers. The Universal versions were largely better. The format has also been known as LV (for LaserVision, actually a player brand by Philips). The players are also sometimes referred to as VDPs (Video Disc Players).

History

Laserdisc technology, using a transparent disc, was invented by David Paul Gregg in 1958 (and patented in 1961 and 1969). By 1969 Philips had developed a videodisc in reflective mode, which has great advantages over the transparent mode. MCA and Philips decided to join their efforts. They first publicly demonstrated the videodisc in 1972. It was first available on the market, in Atlanta, on December 15, 1978, two years after the VHS VCR and five years before the CD, which is based on laserdisc technology. Philips produced the players and MCA the discs. The Philips/MCA cooperation was not successful, and discontinued after a few years.

There are more than 1 million players in home use in the U.S. (compared to 85 million VCRs), and more than 4 million in Japan (or 10% of households). LD has been completely replaced by DVD in the North American retail marketplace, as both players and software are no longer produced there. Laserdisc has retained some popularity among American collectors and to a greater degree, in Japan, where the format was better supported and more prevalent during its life. In Europe, on the other hand, LD has always remained an extremely obscure format.

Technical Information

Software

Resembling a large audio Compact Disc, the standard movie laserdisc disc was 12 inches (30 cm) in diameter and made up five components: two single-sided layer stamped aluminium discs bonded with glue and sandwiched between two sheets of plastic. Laserdisc is an analog format, unlike the modern CD or DVD which are digital formats. Both formats are pressed with pits and lands making up the structure of the disc. On a digital audio CD (or DVD) the pits and lands will signify binary codes; with a Laserdisc, the pits and lands are created using frequency modulation of an analog signal, with the frequency carrier encoded using pulse-width modulation. Additionally, all laserdiscs could be encoded with chapters akin to tracks and display several modes of time, such as "elapsed", "left in chapter", and "left in side".

Audio could be stored in either analog or digital format and in a variety of surround sound formats; NTSC discs could carry two analog audio tracks, plus two uncompressed PCM digital audio tracks, which were CD quality. PAL discs could carry one pair, either analog or digital; in the UK the term LaserVision is used to refer to discs with analogue sound, while LaserDisc is used for those with digital audio. Dolby Digital (also called AC-3) and DTS, which are now common on DVD titles, first became available on Laserdisc, and Star Wars: Episode I (1999) which was released on Laserdisc in Japan, is among the first home video releases ever to include 6.1 channel Dolby Digital EX Surround. Unlike DVDs, which carry Dolby Digital audio in digital form, Laserdiscs store Dolby Digital in a frequency modulated form within a track normally used for analog audio. Extracting Dolby Digital from a Laserdisc required a player equipped with a special "AC-3 RF" output and an external demodulator in addition to an AC-3 decoder. The demodulator was necessary to convert the 2.88 MHz modulated AC-3 information on the disc into a 384 kbit/s signal that the decoder could handle. DTS audio took the place of the PCM audio tracks, and required only a direct connection via Optical Audio cable and a decoder to be heard.

At least where the digital soundtracks were concerned, the level of sound quality was unsurpassed at the time, but the quality of the analog soundtracks varied greatly depending on the disc and, sometimes, the player. Many early and lower-end LD players had poor analog audio sections, and many early discs had poor analog audio tracks, making Digital soundtracks in any form most desirable to serious enthusiasts once they became available. Early Discovision and Laserdisc titles lacked the digital audio option, but many of those movies received digital sound in later re-issues by Universal, and the quality of analog audio tracks generally got better as time went on. Many discs that had originally carried old analog stereo tracks received new Dolby Stereo and Dolby Surround tracks instead, often in addition to a digital track, helping boost sound quality. Later discs also applied CX Noise Reduction, which improved the signal-noise ratio of analog audio. In addition many later PAL discs have no analog audio track at all, instead offering the choice of the PCM digital audio track or Dolby Digital.

Laserdiscs were recorded in one of three formats.

CAV (Constant Angular Velocity) or Standard Play discs contained the several unique features such as freeze frame, variable slow motion and reverse. CAV discs were spun at a constant rotational speed during playback, with one video frame read per revolution and in this mode, 54,000 individual frames or 30 minutes of audio/video could be stored on a single side of a CAV disc. Another unique attribute to CAV was to reduce the visibility of cross talk from adjacent tracks, since on CAV discs any crosstalk at a specific point in a frame is simply from the same point in the next or previous frame. CAV was used less frequently than CLV, reserved for special editions of feature films to highlight bonus material and special effects.

CLV (Constant Linear Velocity) or Extended Play discs do not have the "trick play" features of CAV, offering only simple playback on all but the high-end laserdisc players. These high-end laserdisc players could add features not normally available to CLV discs such as variable forward and reverse, and a VCR-like "pause". CLV encoded discs could store 60 minutes of audio/video. The vast majority of titles were only available in CLV.

CAA (Constant Angular Acceleration). In the early 1980s, due to problems with crosstalk distortion on CLV extended play LaserDiscs, Pioneer Video introduced CAA formatting for extended play discs. Constant Angular Acceleration is very similar to Constant Linear Velocity save for the fact that CAA varies the angular rotation of the disc in controlled steps instead of gradually slowing down as a CLV disc is read. With exception to 3M/Imation, all LaserDisc manufacturers adopted the CAA encoding scheme, even though many manufacturers still referred CAA extended play discs ubiquitously as CLV on the disc packaging.

Hardware

Many Laserdisc players manufactured from the late 1980s through the time of the format's death had both composite (red, white and yellow RCA type connectors) and S-Video outputs on the rear panel. When using the S-Video connection, the player would utilize its own internal comb filter, designed to help reduce picture noise by separating the luminance (brightness) and color parts of the signal, while using the composite outputs forced the player to rely on the comb filter of the display device. Although using the S-Video connection was often considered to yield superior results in the late 80s and early 1990s, most of today's mid and high level television sets contain better comb filters than the vast majority of players were equipped with. In these instances, where a player is being used with a more modern display, using the composite output and allowing the display device's internal comb filter to do the work often yields better results.

Laserdisc vs. VHS

LD had a number of advantages over VHS. It featured a far sharper picture with a horizontal resolution of 400 lines for NTSC and 440 lines for PAL discs, while VHS only offered 250 lines. It could handle analog and digital audio where VHS was analog only, and the NTSC discs could store multiple audio tracks. This allowed for extras like director's commentary tracks and other features to be added on to a film, creating "Special Edition" releases that would not have been possible with VHS. Disc access was random and chapter based, like the DVD format, meaning that one could jump to any point on a given disc very quickly (depending on the player and the disc, within a few seconds at the most). (Random access is a general advantage of disc formats.) By comparison, VHS would require tedious rewinding and fast-forwarding to get to specific points. Laserdiscs were cheaper than videocassettes to manufacture, because they lack the moving parts and plastic outer shell that are necessary for VHS tapes to work. (A standard VHS cassette has at least 14 parts including the actual tape. A Laserdisc has one part, with five or six layers.)

Moreover, because the discs are read optically instead of magnetically, no physical contact needs to be made between the player and the disc, except for the player's clamp that holds the disc at its center as it's spun and read. As a result, playback doesn't wear the information-bearing part of the discs, and properly-manufactured LDs will theoretically last beyond one's lifetime. By contrast, a VHS tape holds all of its picture and sound information on the tape in a magnetic coating which rubs directly against the player heads, causing progressive wear with each use. Also, the tape is thin and delicate, and it is easy for a player mechanism (especially on a cheap model) to mishandle the tape and damage it by creasing it, frilling (stretching) its edges, or even breaking it.

The format's support for multiple audio tracks allowed for vast supplemental materials to be included on-disc and made it the first viable format for "Special Edition" releases; the 1984 Criterion Collection edition of Citizen Kane is generally credited as being the first "Special Edition" release to home video, and for setting the standard by which future SE discs were measured. In addition, the format's instant seeking capability made it possible for a new breed of laserdisc-based video arcade games, beginning with Dragon's Lair, to be born.

Unfortunately, the format was not without its disadvantages. The discs were 30cm (12 inches) across, heavy, cumbersome, easier to damage on handling than a VHS cassette, and didn't have recording capabilities. And despite their massive storage capacity, the space-consuming analog video signal LDs couldn't store much video; depending on whether it was a CLV or CAV disc, each side of a given disc was limited to holding either 30 (for CAV discs) or 60 minutes (for CLV discs) of data. After one side was finished playing, a disc would have to be flipped over in order to continue watching the film, and many films required two discs (usually two sides of disc 1 and one side of disc 2) to contain them completely. Many players, especially units built after the mid-1980s, could "flip" discs automatically by rotating the optical pickup to the other side of the disc, but except in high-end models with a pre-read buffer, this was accompanied by a pause in the movie during the side change. In addition, if the movie was longer than what could be stored on 2 sides of a single disc, manually swapping to a second disc would be necessary at some point during the film. To make matters worse, many early LDs were not manufactured properly; sometimes a substandard adhesive was used to sandwich together the two sides of the disc, causing it to delaminate slightly. This would allow air in, which would cause the metallic part of the discs to oxidize. This eventually destroyed the disc as the oxidized aluminum lost its reflective property, a process known as "laser rot" among LD enthusiasts. (Early CDs suffered similar problems, including a notorious batch of defective discs manufactured by Philips-DuPont Optical in Europe during the early 1990s.)

Currently, the LaserDisc movie that has the most reported laser rot is the film Eraser (1996), as noted by the contributors of LaserDisc Database.

Laserdisc vs. DVD

It is interesting to note that the differences between LD technology and DVD have led some videophiles to prefer LD. Laserdiscs use only analog video and almost always carry some form of analog audio. Many purists believe that analog media is capable of higher quality than digital A/V carriers such as CD and DVD, and early DVD demo discs often had compression or encoding problems, giving LD proponents fuel for the fire. However, "LD-perfection" is rarely achieved in practice. Only the absolute best LDs, few and far between, exhibit such superior quality in comparison to the newer DVDs, and even then it requires expensive equipment to realize the benefits.

An advantage to the Laserdisc format over DVD is that video is not digitally-encoded and compressed, and therefore does not experience problems such as artifacting (most visible as blockiness during high motion sequences) or color banding (subtle visible lines in gradient areas, such as skies) that can be caused by the MPEG-2 encoding process as video is prepared for DVD. Fortunately, however, the meticulous frame-by-frame tuning of the encoding process coupled with the variable bit-rate technology generally employed on big-budget DVD releases effectively eliminates this, and an optional feature of the MPEG-2 compression standard allows much higher color resolution to eliminate the visible effect of color banding on some high-end home theatre equipment. Some videophiles will continue to argue that Laserdisc maintains a "smoother" more "film like" image while DVD still looks slightly more artificial.

A disadvantage with the analog nature of Laserdiscs is that most players exhibit a slight but perceivable 30 Hz video flicker. Slight dust and scratches could cause various problems that could affect video quality and possibly also tracking accuracy of the disc by the player. Wearout and/or calibration drift on the hardware could also play a role in degrading video quality, audio quality, and tracking accuracy. The DVD format, however, does not introduce any flicker, and the format's digital nature and sophisticated error-correction scheme can often produce spotless video/audio from a DVD, even with dust and scratches on the surface to a certain extent.

Laserdisc players sometimes suffered a problem known as "crosstalk" on extended play discs, usually with equipment requiring service of the laser optical pickup assembly when this occurs. However, the problem with crosstalk may also occur with poorly manufactured CLV LaserDiscs or with discs that are excessively warped. The issue came up when the optical pickup inside the player accidentally picked up the encoded video information from a track adjacent to where it was reading on the disc. The added information usually showed up as distortion in the picture, usually looking reminiscent of and referred to as "barber poles." Some players were better at compensating for and/or avoiding crosstalk entirely than others, provided that the cause of crosstalk was the disc and not the player. However, there is no crosstalk distortion on CAV standard play LaserDiscs as the rotational speed never varies. But, if the player calibration is out of order or if the CAV disc is faulty, other problems affecting tracking accuracy could occur, such as "laser lock," a problem where the player reads the same track and, thus, the same two fields for one frame over and over again, causing the picture to freeze as if in pause.

DVD image resolution is also greater than Laser Disc. Most DVD players allow an anamorphic transfer of a 16:9 movie to be downconverted into letterbox or pan & scan for TVs that don't support anamorphic display, while very few LD players supported this feature, necessitating the issue of separate editions.

Another major advantage to DVD over Laserdisc was the fact that LD playback quality was highly dependent on player quality (as with any analog format). On most television sets, a given DVD player will produce a picture that is visually indistinguishable from other units; quality differences between players only become easily apparent with higher-end equipment. This was not true of Laserdisc playback quality; major variances in picture quality could appear between different makes and models of LD player, even when tested on a TV that was not particularly high-end. This fact has had long lasting ramifications, as the pricing for what were considered to be good players has remained comparably high (anywhere from $200 to well over $1,000 USD), while older and less desirable players can be purchased in working condition for as little as $25.

Success of the format

The format was not well-accepted outside of videophile circles in North America, but became more popular in Japan. Part of the reason was marketing. In North America, the cost of the players and discs were kept far higher than VHS decks and tapes. In Japan, the LD strategy was very similar to the strategy taken by DVD manufacturers early in its life: prices were kept low to ensure adoption, resulting in minimal price differences between VHS tapes and the higher quality Laserdiscs. LD also quickly became the dominant format of choice amongst Japanese collectors of anime, helping to drive its acceptance.

Nonetheless, the Laserdisc format did not allow for recording onto the discs, while the competing video cassette recorder devices could record using tape cassettes. Combined with the inconvenient disc size and high North American prices for both players and media, the format was doomed to obscurity. When they were first introduced, LaserDiscs were believed to be what would later be referred to as disruptive technology, a promise they failed to fulfill. Compact Discs and DVDs were to be disruptive instead.

Although the Laserdisc format has been completely supplanted by DVD, and new players are no longer sold outside Japan, many LDs are still highly coveted by movie enthusiasts. This is largely because there are many films that are still only available on LD and many other LD releases contain supplemental material not available on subsequent DVD versions of those films. As well, there are various films which are available on DVD as well as LD, but the LD version is preferred for some reason.

The most notable example is the Criterion Collection release of Blade Runner, as it is the highest quality release of BR to contain a widescreen transfer of the theatrical cut of the film, whereas other releases have been only in pan and scan or of the so-called Director's Cut of the movie. Other examples include the LD release of the anime Five Star Stories, which prior to its long-awaited release on DVD fetched as much as $700 from enthusiasts. Likewise, the LD releases of the original Star Wars films are in high demand among fans and videophiles as they offer the highest quality widescreen presentations of the films in their original theatrical cuts, sans the digital characters and effects added by George Lucas for the "Special Edition" releases of those films. This LD-only widescreen experience even applies to children's classics, like the Reader's Digest-produced 1970s musical versions of Tom Sawyer and Huckleberry Finn, which are only available in pan-and-scan versions on VHS and have yet to be released on DVD. In fact, due to a contract bind, the pilot episode of Twin Peaks as seen in the United States may never be released on DVD, and the LD release is the only way to see it outside of VHS.

LD players are also sometimes found in contemporary North American high school and college physics classrooms, in order to play a disc of the Physics: Cinema Classics series of mid-20th century Encyclopædia Britannica films reproducing classic experiments in the field which are difficult or impossible to replicate in the laboratories in educational settings. These films have yet to be released on DVD.

It should be noted that the popularity of the LD format in Japan is still great enough that Pioneer continues to manufacture and market two players. The first, the DVL-919, is a DVD/Laserdisc combination unit that was sold for a short while in the U.S. and was subsequently discontinued in 1999 when the format had lost the vast majority of its waning support. In any case, even the least expensive of newer DVD players have generally surpassed the quality and capability of the 919's DVD section and its LD section was never considered better than mediocre by comparison to many other units, even when new. The second of the units offered in Japan, a Laserdisc-only player, model designation CLD-R5, is sold at a lower cost. Although rumor has had it that select Pioneer dealers still have access to leftover, North American specification DVL-919s, and Pioneer has yet to remove the product from their North American website, Pioneer representatives say that the product is officially discontinued and that warranty coverage for 919s will be based on the date of manufacturing rather than on the date of sale.

An interesting note is that David Letterman apparently owned a DVL-919. He spent part of a 1999 show complaining that his DVD of "Lawrence of Arabia" had a heavy blue tint to it. The next night, after a call from a Pioneer Representative, he explained that he owned a DVD/LD combo player, and Pioneer assured him that the problem was due to the "wrong filter" reading the disk. As the only combo player available in the US at the time was the 919, one assumes this was the player he owned. Coincidentally, Pioneer offered Dave a new DVD-only player as well.

Certain Japanese players, which are considered to be of higher quality or of greater capacity for quality playback than the North American units, are occasionally imported by enthusiasts. These include the LD-S9, HLD-X9 and HLD-X0. All three are manufactured by Pioneer and all three contain technology that was never officially available in North American Laserdisc players. The LD-S9 and HLD-X9 share a highly advanced comb filter, allowing them to offer a considerable advantage in picture quality over most other LD players when the s-video connection is used. The comb filter present in these players is unique and is purportedly the finest comb filter ever used in consumer A/V gear, it is still currently in use in Mitsubishi's top-spec CRT rear projection television sets (the Diamond and now defunct Platinum series sets) and Pioneer's Elite line of rear projection televisions. In addition to the advanced comb filter, the HLD-X9 contains a red laser pickup which significantly reduces crosstalk and picture-noise levels compared to players with the traditional infrared laser; it can also read through all but the worst cases of laser rot and surface wear. The HLD-X9 is, lastly, also a MUSE player, capable when properly equipped of playing back high definition laserdiscs, called Hi-Vision or MUSE discs in Japan. The HLD-X0 is Pioneer's original MUSE player, and is the player of choice for many enthusiasts despite the fact that it lacks the comb filter shared by the S9 and X9. It was entirely hand built from hand picked electronics and weighed a massive 36 kilograms. Many argue that the newer X9 was a more capable MUSE player but that the X0 had superior performance with standard NTSC discs. Nonetheless, the X9 remains the more popular of the two models, as it includes the newer comb filter and is a dual-side player, meaning that double sided discs don't need to be manually flipped over in order for both sides to be played.

Laserdisc variations

Early in the eighties, philips produced a laservision player model adapted for a computer interface, dubbed 'professional'. When hooked to a PC this combination could be used to display images or information for educational or archival purposes, for example thousands of scanned medieval manuscripts. This strange device could be considered a very early equivalent of a CD-ROM. In one case such a 'laserdisc-rom' was still present, although rarely used, in 2001.

In 1991, several manufacturers announced specifications for what would become known as MUSE Laserdisc. Encoded using NHK's MUSE "Hi-Vision" analogue TV system, MUSE discs would operate like standard Laserdiscs but would contain high-definition 1125-line (1035 visible lines) video with a 5:3 aspect ratio. The MUSE players were also capable of playing standard NTSC format discs and are said to have superior performance to non-MUSE players. The MUSE-capable players had several noteworthy advantages over standard Laserdisc players, including a red laser with a much narrower wavelength than the lasers found in standard players. The red laser was capable of reading through disc defects such as scratches and even mild disc-rot that would cause most other players to stop, stutter or drop-out. Crosstalk was not an issue with MUSE discs, and the narrow wavelength of the laser allowed for the virtual elimination of crosstalk with normal discs. In order to view MUSE encoded discs, it was necessary to have a MUSE decoder in addition to a compatible player and a MUSE-compatible TV set. Equipment prices were high, especially for early HDTVs which generally eclipsed $10,000 USD, and even in Japan the market for MUSE was tiny. Players and discs were never officially sold in North America, although several distributors imported MUSE discs along with other import titles. Terminator 2: Judgment Day, Lawrence of Arabia, A League of Their Own, Bugsy, Close Encounters of the Third Kind, Bram Stoker's Dracula and Chaplin were among the theatrical releases available on MUSE LDs. Several documentaries, including one about Formula One at Japan's Suzuka Circuit were also released.

Towards the end of the format's life, a small number of discs were sold in Japan which contained an anamorphic image technology marketed as "squeeze", effectively the same as the 16:9 anamorphic output from a DVD player. Among the very few films available in this format were Terminator 2: Judgment Day, Basic Instinct, and Cliffhanger. Unlike MUSE discs, Squeeze titles required a widescreen television set to display the squeezed image correctly, and they ran at standard resolution, offering 400 horizontal lines (they were mainly NTSC, only two PAL "Squeeze" titles were produced). Widescreen sets cost considerably more than a standard set at the time, which played a major part in why the format never caught on.

"LD singles" which are 18 cm (approx. 8", one inch larger in diameter than a standard 45-RPM record) across rather than the full 30 cm (approx. 12") size, were also published. LD singles only contained a few minutes of video, enough for a music video or two. They are much rarer than the full-size LDs, especially in North America.

Other forms of "single"-style discs that were playable on laserdisc players were CD Video (CD-V) discs, and Video Single Discs (VSD). A CD-V carried up to 5 minutes of analog laserdisc-type video content (usually a music video), as well as up to 20 minutes of digital audio CD tracks. CD-Vs are not to be confused with Video CDs, which are all digital, and can only be played on computers, CD-i players, DVD players, VCD players, and later-model laserdisc players (such as the DVL series from Pioneer) that can also play DVDs. VSDs were the same as CD-Vs, but without the audio CD tracks. CD-Vs were somewhat popular for a brief time worldwide, but soon faded from view. VSDs were popular only in Japan and other parts of Asia, and were never really introduced to the rest of the world. Both CD-V and VSD used a 5-inch disc, much like audio CD.

Some laser discs, called "picture discs", have artistic etching on one side of the disc to make the disc more visually attractive than the standard shiny silver surface. This etching might look like a movie character, logo, or other promotional material. Sometimes that side of the LD would be made with colored plastic rather than the clear material used for the data side. Picture disc LDs only had video material on one side as the "picture" side could not contain any data. Picture discs are rare in North America.

Pioneer Electronics, one of the format's largest supporters/investors, was also deeply involved in the karaoke business in Japan, and used laserdiscs as the storage medium for music and additional content such as graphics. The format was generally called LD+G. While several other karaoke labels manufactured laserdiscs, there was nothing like the breadth of competition in that industry that exists now, as almost all manufacturers have transitioned to CD+G discs (en route, possibly, to a new DVD based format).

Pioneer also marketed a format similar to LD+G, called LD-ROM. It was used by Pioneer's LaserActive interactive laserdisc player/video game console introduced in 1993, and contained analog video in combination with digital data. LD-ROM was used for several games that could be played on the LaserActive player/console.

A CRV Disc with a VHS tape for size comparison

Another type of video media, CRVdisc, or "Component Recordable Video Disc" were available for a short time, mostly to professionals. Developed by Sony, CRVdiscs resemble early PC CD-ROM caddies with a disc inside resembling a full sized LD. CRVdiscs were blank media that could be recorded once on each side (much like WORM media, such as CD-R discs). CRVdisc was rarely used by the consumer due to the high cost of the equipment and media, and were used largely for backup storage in professional/commercial applications.

Another form of recordable laserdisc that is completely playback-compatible with the Laserdisc format (unlike CRVdisc, due to its caddy enclosure) is the RLV, or Recordable LaserVision disc. It was developed and first marketed by the Optical Disc Corporation (ODC, now ODC Nimbus) in 1984. RLV discs, like CRVdisc, are also a WORM technology, and function exactly like a CD-R disc. RLV discs look almost exactly like standard laserdiscs, and can play in any standard laserdisc player after they've been recorded. The only difference an RLV disc has over regular factory-pressed laserdiscs is their reflective purple-violet color resulting from the dye embedded in the reflective layer of the disc to make it recordable, as opposed to the silver mirror appearance of regular LDs. The color of RLVs look almost exactly like the purplish color of the dye used for some DVD-R and DVD+R discs. RLVs were popular for making short-run quantities of laserdiscs for specialized applications such as interactive kiosks and flight simulators.

Significant Players

External links

Video storage formats

Videotape

Analog	Quadruplex (1956) VERA (1958) Ampex 2 inch helical VTR (1961) Sony 2 inch helical VTR (1961) Type A (1965) CV-2000 (1965) Akai (1967) EIAJ-1 (1969) U-matic (1971) Cartrivision (1972) Philips VCR (1972) V-Cord (1974) VX (videocassette format) (1974) Betamax (1975) IVC (1975) Type B (1976) Type C (1976) VHS (1976) Akai VK (1977) Video Cassette Recording (1979) Video 2000 (1980) Compact Video Cassette (1980) VHS-C (1982) M (videocassette format) (1982) Betacam (1982) Video8 (1985) Betacam SP (1986) MII (1986) S-VHS (1987) S-VHS-C (1987) Hi8 (1989) Ruvi (1998)
Digital	D1 (1986) D2 (1988) D3 (1991) DCT (videocassette format) (1992) Digital Betacam (1993) D5 (1994) Digital-S (D9) (1995) Betacam SX (1996) Digital8 (1999) MPEG IMX (2000) MicroMV (2001)
High Definition	Sony HDVS (1984) UniHi (1984) BCH 1000 (1992) W-VHS (1994) HDCAM (1997) D-VHS (1998) D6 HDTV VTR (2000) HDV (2003) HDCAM SR (2003)

Videodisc

Analog	Phonovision (1927) Ampex-HS (1967) TeD (1975) LaserDisc (1978) CED (1981) VHD (1983) Laserfilm (1984) CD Video (1987) VSD (1990)
Digital	Video CD (1993) MovieCD (1996) DVD (1996) MiniDVD (c. 1996) CVD (1998) Super Video CD (1998) EVD (2003) PVD (Personal Video Disc) (2003) Universal Media Disc (2004) Forward Versatile Disc (2005)
High Definition	MUSE Hi-Vision LD (1994) Professional Disc (2003) High-Definition Versatile Disc (2004) VMD (2006) HD DVD (2006) Blu-ray Disc (2006) MiniBD (c. 2006) Holographic Versatile Disc (2007) China Blue High-definition Disc (2008)
Ultra-High Definition	Ultra HD Blu-ray (2016)

Virtual

Media agnostic	DV (1995) DVCPRO (1995) DVCAM (1996) DVCPRO50 (1997) DVCPRO HD (2000)
Tapeless	CamCutter Editcam (1995) XDCAM (2003) GBA-TV (2004) MOD (2005) AVCHD (2006) AVC-Intra (2006) TOD (2007) iFrame (2009) XAVC (2012)
Solid state	P2 (2004) SxS (2007) MicroP2 (2012)

Video recorded to film

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