8 mm video format

The 8mm video format refers informally to three related videocassette formats for the NTSC and PAL/SECAM television systems. These are the original Video8 (analog recording) format and its improved successor Hi8 (analog video and analog audio but with provision for digital audio), as well as a more recent digital recording format known as Digital8.

Their user base consisted mainly of amateur camcorder users, although they also saw important use in the professional television production field.

In January 1984, Eastman Kodak announced the new technology.[1][2] In 1985, Sony of Japan introduced the Handycam, one of the first Video8 cameras with commercial success. Much smaller than the competition's VHS and Betamax video cameras, Video8 became very popular in the consumer camcorder market.

8mm Video
8mm video cassette front
A Video8 videocassette
Media typeMagnetic tape
EncodingNTSC, PAL, SECAM
CapacityVideo8/Hi8:
60 minutes (PAL-SP)
90 minutes (PAL-SP)
135 minutes (PAL-SP)
120 minutes (NTSC-SP)
Digital8:
60 minutes (NTSC-SP)
90 minutes (PAL-SP)
Read mechanismHelical scan
Write mechanismHelical scan
StandardInterlaced video
Developed bySony and Kodak
UsageHome movies

Technical overview

The three formats are physically very similar, featuring both the same magnetic tape width and near-identical cassette shells, measuring 95 × 62.5 × 15 mm. This gives a measure of backward compatibility in some cases. One difference between them is in the quality of the tape itself, but the main differences lie in the encoding of the video when it is recorded onto the tape.

Video8 was the earliest of the three formats, and is entirely analog. The 8mm tape width was chosen as smaller successor to the 12mm Betamax format, using similar technology (including U-shaped tape loading) but in a smaller configuration in response to the small configuration VHS-C compact camcorders introduced by the competition. It was followed by Hi8, a version with improved resolution. Although this was still analog, some professional Hi8 equipment could store additional digital stereo PCM sound on a special reserved track.

Digital8 is the most recent 8mm video format. It retains the same physical cassette shell as its predecessors, and can even record onto Video8 (not recommended) or Hi8 cassettes. However, the format in which video is encoded and stored on the tape itself is the entirely digital DV format (and thus very different from the analog Video8 and Hi8). Some Digital8 camcorders support Video8 and Hi8 with analog sound (for playback only), but this is not required by the Digital8 specification.

In all three cases, a length of 8mm-wide magnetic tape is wound between two spools and contained within a hard-shell cassette. These cassettes share similar size and appearance with the audio cassette, but their mechanical operation is far closer to that of VHS or Betamax videocassettes. Standard recording time is up to 180 minutes for PAL and 120 minutes for NTSC. (The cassette holds the same length tape; tape consumption is different between PAL and NTSC recorders.)

Like most other videocassette systems, Video8 uses a helical-scan head drum (it having a small 40mm head) to read from and write to the magnetic tape.[3] The drum rotates at high speed (one or two rotations per picture frame—about 1800 or 3600 rpm for NTSC, and 1500 or 3000 rpm for PAL) while the tape is pulled along the drum's path. Because the tape and drum are oriented at a slight angular offset, the recording tracks are laid down as parallel diagonal stripes on the tape.

Unlike preceding systems, 8mm did not use a control track on the tape to facilitate the head following the diagonal tracks. Instead 8mm recorded a sequence of four sine waves on each video track such that adjacent tracks would produce one of two heterodyne frequencies if the head mistracked. The system automatically adjusted the tracking such that the two frequencies produced were of equal magnitude. This system was derived from the dynamic track following (DTF) used by the Philips Video 2000 system. Sony rechristened the system as automatic track following (ATF) as the 8mm system lacked the ability of the heads to physically move within the head drum.

The main disadvantage of the ATF system was that unlike in the case of a control track, an 8mm camera or player cannot keep track of where the tape is during fast forward and rewind (though it could during shuttle search). This made editing using a linear editing system problematic. Some later cameras and players attempted to derive the tape position from the differential rotation of the spools with limited success.

Generations

8mmCamcorder
An amateur grade Video8 Camcorder from the early 1990s.

Video8

Video8 was launched in 1985, into a market dominated by the VHS-C and Betamax formats.[4] The first model was the Sony Handycam CCD-V8, a record only model with no play back features, only three focus settings and a 6x zoom.[5][6][7] Soon after, an Auto-focus model was introduced.[6]

In terms of video quality, Video8 and Beta-II offer similar performance in their standard-play modes. In terms of audio, Video8 generally outperforms its older rivals. Standard VHS and Beta audio is recorded along a narrow linear track at the edge of the tape, where it is vulnerable to damage. Coupled with the slow horizontal tape speed, the sound was comparable with that of a low-quality audio cassette. By contrast, all Video8 machines used audio frequency modulation (AFM) to record sound along the same helical tape path as that of the video signal. This meant that Video8's standard audio was of a far higher quality than that of its rivals, although linear audio did have the advantage that (unlike either AFM system) it could be re-recorded without disturbing the video. (Betamax and VHS Hi-Fi rarely appeared on camcorders, except on the high-end models.) Video8 later included true stereo, but the limitations of camcorder microphones at the time meant that there was little practical difference between the two AFM systems for camcorder usage. In general, Video8 comfortably outperforms non-HiFi VHS/Beta.

Video8 has one major advantage over the full-size competition. Thanks to their compact size, Video8 camcorders are small enough to hold in the palm of the user's hand. Such a feat was impossible with Betamax and full-sized VHS camcorders, which operate best on sturdy tripods or strong shoulders. Video8 also has an advantage in terms of time, because although VHS-C offers the same "palmcorder" size as Video8, the VHS-C tapes only hold, at most, 45 minutes of tape in SP speed. Thus, Video8's 120-minute capacity served well for most users during its peak. (Both machines include longer playing modes at 120 and 240 minutes, respectively, but at the cost of reduced-quality images.) Longer sessions generally require additional infrastructure (line power or more batteries), and hence longer recording times offer little advantage in a true travelling environment.

Video8/Hi8's main drawback is that tapes made with Video8 camcorders cannot be played directly on VHS hardware. Although it is possible to transfer tapes (using the VCR to rerecord the source video as it is played back by the camcorder), this inevitably leads to degradation of the analog signal. During the 1990s Sony did market a few VHS VCRs that also feature an 8mm deck to allow convenient transfer to VHS. GoldStar also made a similar dual-deck machine.

Ultimately, Video8's main rival in the camcorder market turned out to be VHS-C, with neither dominating the market completely. However, both formats (along with their improved descendants, Hi8 and S-VHS-C) were nevertheless very successful. Collectively, they dominated the camcorder market for almost two decades before they were eventually crowded out by digital formats, such as MiniDV and 8cm DVD.

Hi8

To counter the introduction of the Super-VHS format, Sony introduced Video Hi8 (short for high-band Video8). Like S-VHS, Hi8 uses improved recorder electronics and media formulation to increase the recorded bandwidth of the luminance signal. Both Hi8 and S-VHS were officially rated at a luminance resolution of 400 lines,[8] a vast improvement from their respective base formats and are roughly equal to Laserdisc quality. Chroma resolution for both remain unchanged.[3]

Both S-VHS and Hi8 retain the audio recording systems of their base formats; VHS HiFi Stereo outperforms Video8/Hi8 AFM, but remains restricted to high-end machines. In the late 1980s, digital (PCM) audio was introduced into some higher-grade models of Hi8 recorders. Hi8 PCM audio operates at a sampling rate of 32 kHz with 8-bit samples—higher fidelity than the monaural linear dubbing offered by VHS/S-VHS, but vastly inferior to VHS HiFi. PCM-capable Hi8 recorders can simultaneously record PCM stereo in addition to the legacy (analog AFM) stereo audio tracks.

The final upgrade to the Video8 format came in 1998, when Sony introduced XR capability (extended resolution). Video8-XR and Hi8-XR offers a modest 10% improvement in luminance detail. XR equipment replays non-XR recordings well, and XR recordings are fully playable on non-XR equipment, though without the benefits of XR.

All Hi8 equipment can record and play in the legacy Video8 format. The reverse is not usually the case though there are a few late-entry Video8 systems that recognize and play Hi8 recordings.

PCM Multi Audio

The Sony EV-S900 (Hi8), Sony EV-S800, Sony EV-S700U, and Pioneer VE-D77 (Video8) all support a mode called "PCM Multi Audio Recording". While other 8mm decks support only a single stereo PCM recording, these units provide five additional stereo PCM tracks that are recorded in the video area of the signal. This allows 8mm tapes to hold 6 parallel tracks of audio, each up to 4 hours long (in LP mode). Only one stereo track can be recorded or listened to at a time, and tracks are selected with the "PCM Multi Audio" selector button.

Digital8

Hitachi d8
Hitachi Digital8 Camcorder.

Introduced in 1999, Digital8 is a form of the industry standard DV codec, recorded on Hi8 media. In engineering terms, Digital8 and MiniDV are indistinguishable at the logical format level. To store the digitally encoded audio/video on a standard NTSC Video8 cassette, the tape must be run at double the Hi8 speed. Thus, a 120-minute NTSC Hi8 tape yields 60 minutes of Digital8 video. Most Digital8 units offer an LP mode, which increases the recording time on an NTSC P6-120 tape to 90 minutes.

For PAL, the Digital8 recorder runs 1½ times faster; thus, a 90-minute PAL Hi8 tape yields 60 minutes of Digital8 video. PAL LP mode returns the tape speed to the Hi8 SP speed, so a Hi8 90-minute tape yields 90 minutes of Digital8 video.

Sony has licensed Digital8 technology to at least one other firm (Hitachi), which marketed a few models for a while; but as of October 2005 only Sony sells Digital8 consumer equipment. Digital8's main rival is the consumer MiniDV format, which uses narrower tape and a correspondingly smaller cassette shell. Since both technologies share the same logical audio/video format, Digital8 can theoretically equal MiniDV or even DVCAM in A/V performance. But as of 2005, Digital8 has been relegated to the entry-level camcorder market, where price, not performance, is the driving factor. Meanwhile, MiniDV is the de facto standard of the domestic digital tape camcorder market.

Digital8 recordings are not interchangeable with analog recordings, although many models of Digital8 equipment are able to play Hi8/Video8 analog recordings.

Tape and recording protection

8mm video cassette
The write-protect switch (right) prevents accidental erasure.

As with many other video cassette formats, 8mm videocassettes have a tape-protecting mechanism built into the shell. Unlike the ones on VHS and VHS-C shells, which consist of only a single piece of plastic that protects the part of the tape that is read by the player/recorder, Hi8's tape-protection mechanism consists of two pieces of plastic at the top of the shell that come together and form a casing that protects both sides of the tape, and a latch that prevents this casing from opening and exposing the tape. The playback/recording unit can depress this latch to open the casing and gain access to the tape.

To prevent the recording on the tape from being erased, there is a small write-protect tab that can be moved to one of two positions, labeled "REC" and "SAVE". Comparing the sliding tab to a door, the tape is in the "REC" position when the "door" is open and in the "SAVE" position when it is closed. (Not all tape cases have markings for this information.) The tape can only be recorded onto (or recorded over) when this tab is in the "REC" position. This is an improved version of the VHS write-protect tab, which prevents erasure after it has been broken off, requiring covering with adhesive tape or filling with an obstruction to remove the write protection.

Video8 outside the camcorder market

The home market

Cannon ES-100A
Canon ES-100A: High-end Video 8 VCR based on the Sony EV-S1.

Efforts were made to expand Video8 from only the camcorder market into mainstream home video. But as a replacement for full-size VCRs, Video8 failed. It lacks the long (5+ hours) recording times of both VHS and Betamax, offers no clear audio/video improvement, and cost more than equivalent full-size VCRs. Even with all of the advanced features offered in high-end Video8 machines, there was no compelling reason to switch to Video8 for the home application.

Initially, many movies were prerecorded in 8mm format for home and rental use, but the rental market for Video8 never materialized. Sony maintained a line of Video8 home VCRs well into the 1990s, but unlike VHS, 8mm VCRs with timers were very expensive.

Sony also produced a line of Video8 Walkman-branded players and recorders, with and without a flip-up screen meant for video playback and limited recording. These have been adapted for Digital8 as well as MiniDV formats, even as portable DVD players have become popular in this application. Such players saw use in professional applications, particularly with airlines, who, during the 1980s, adopted 8mm as the format for in-flight movies. As of 2008, they remained in use on many airliners.

Hi8 3CCD-camcorder Sony EVW-300
A professional-grade ENG/EFP field Hi8 camcorder. Sony EVW-300

Videography

Among home and amateur videographers, Video8/Hi8 was popular enough for Sony to make equipment for video editing and production. The format also saw some use in professional electronic news gathering and electronic field production.

Decline

By 2009, the popularity of the analog 8mm formats had dwindled considerably and new camcorders that support the format were unobtainable, having been superseded by digital formats, mainly MiniDV and 8 cm DVD. These in turn have been largely displaced by high-definition camcorders that record to flash storage cards. Both Video8 and Hi8 blank media remain available and affordable but are increasingly rare. Tape-based camcorders are still readily available in the second hand market. The last Hi8 camcorder (the Sony CCD-TRV238) and the last Digital8 camcorder (the Sony DCR-TRV285) were both discontinued in 2007, ending the 8mm format's 22 years.

Miscellaneous technical problems

Dropouts

In Video8 and its successors, the smaller head drum and tape make recorders more susceptible to the effects of "tape dropout", where magnetic particles are eroded from the tape surface. As the audio/video signal is contained in a smaller area on a Video8 tape, a single dropout has a more damaging effect. Hence, dropout compensation in Video8 systems tend to be more advanced in order to mitigate the format's vulnerability to dropouts. In this respect, VHS's and Betamax's larger head drums proved advantageous.

Lifespan of 8mm tapes

8mm tapes should be stored vertically, out of direct sunlight, in a dry, cool, dust-free environment. As with any media, they will eventually deteriorate and lose their recorded contents over time, resulting in a buildup of image noise and dropouts. Tapes more than 15 years old may start to show signs of degradation. Among other problems, they can become sticky, jamming playback units, or become brittle and snap. Such problems will normally require professional attention.

However, the 8mm format is no more prone to this than any other magnetic tape format. In fact, the metal-particle technology used with the Video8 formats is more durable than the metal-evaporated type used with MiniDV. Hi8 tapes can be either of Metal Particle (MP) or Metal Evaporated (ME) formulation.

Because 8mm tapes use a metal formulation, they are harder to erase than the oxide tapes used with VHS, S-VHS, and Betamax tapes. As such, carefully stored, they are less susceptible to magnetic fields than the older formats.

See also

  • Data8 – Data format for very similar media.
  • Ruvi – a unique camcorder based on Hi8 tape.

References

  1. ^ Nmungwun, Aaron Foisi (2012-11-12). Video Recording Technology: Its Impact on Media and Home Entertainment. Routledge. ISBN 9781136466045. Archived from the original on 2018-05-15.
  2. ^ Schrage, Michael; Schrage, Michael (1984-01-05). "Kodak Unveils 8mm Video 'Camcorder'". The Washington Post. ISSN 0190-8286. Archived from the original on 2017-08-28. Retrieved 2017-06-07.
  3. ^ a b Beeching, Steve (2001). Video and Camcorder Servicing and Technology. Newnes. ISBN 0-7506-5039-7.
  4. ^ "History of Video Now and Then". Archived from the original on 2015-04-27. Retrieved 2015-04-20.
  5. ^ "Sony's Handycam Camcorder Celebrates Its 25th Anniversary – Sony Insider". sonyinsider.com. Archived from the original on 2015-04-10.
  6. ^ a b Carter, Rodger. "1984_1985". www.digicamhistory.com. Archived from the original on 2014-02-09.
  7. ^ "Sony Global - Product & Technology Milestones-Video Camera". www.sony.net. Archived from the original on 2015-05-02.
  8. ^ "How Camcorders Work". howstuffworks.com. 10 October 2000. Archived from the original on 30 January 2012.

External links

8 mm

8 mm may refer to:

Film technology8 mm film, a photographic cine film format principally intended for domestic use. The term may also refer to later variants:

Super 8 mm film

Single-8 film

8 mm video format, a type of video recorder and tape that is primarily used in camcorders, including Video 8 and Hi 8

Digital8 video tape formatFirearms8 mm caliber, ammunition with bullet in the 8 mm (.315 in) caliber range

7.92×57mm Mauser "8 mm Mauser cartridge" – a rifle cartridge originating in Germany (though not designed by the Mauser company)Other uses8mm (band), pop-rock band from Los Angeles, California

8mm (film), about a private detective trying to verify the authenticity of a snuff film

Camcorder

A camcorder is an electronic device originally combining a video camera and a videocassette recorder.

The earliest camcorders were tape-based, recording analog signals onto videotape cassettes. In 2006, digital recording became the norm, with tape replaced by storage media such as mini-HD, microDVD, internal flash memory and SD cards.More recent devices capable of recording video are camera phones and digital cameras primarily intended for still pictures; the term "camcorder" may be used to describe a portable, self-contained device, with video capture and recording its primary function, often having advanced functions over more common cameras.

Data8

The 8 mm Backup Format is a magnetic tape data storage format used in computer systems, pioneered by Exabyte Corporation. It is also known as Data8, often abbreviated to D8 and is written as D-Eight on some Sony branded media. Such systems can back up up to 60 GB of data depending on configuration. The tapes used are mechanically the same as the tapes used in 8 mm video format recorders and camcorders.

Until the advent of AIT, Exabyte were the sole vendor of 8 mm format tape drives. The company was formed with the aim of taking the 8 mm video format and making it suitable for data storage. They did so by building a reliable mechanism and data format that used the common 8 mm helical scan video tape technology that was available then.

Exabyte's first 8 mm tape drive was made available in 1987. This was followed up with their Mammoth tape drive in 1996, and the Mammoth-2 (M2) in 1999.

Exabyte's drive mechanisms were frequently rebranded and integrated into UNIX systems.

Digital8

Digital8 (or Di8) is a consumer digital recording videocassette for camcorders based on the 8 mm video format developed by Sony, and introduced in 1999.

The Digital8 format is a combination of the earlier analog Hi8 tape transport with the digital DV codec. Digital8 equipment uses the same videocassettes as analog recording Hi8 equipment, but the signal is encoded digitally using the industry-standard DV codec, which means it has identical digital audio and digital video specifications compared with DV.

To facilitate digital recording on existing Hi8 video cassettes the helical scan video head drum spins 2.5× faster. For both NTSC and PAL Digital8 equipment, a standard-length 120-minute NTSC/90-minute PAL Hi8 magnetic tape cassette will store 60 minutes of Digital8 video (Standard Play) or 90 minutes (Long Play). LP is model specific, such as the TRV-30, TRV-40, and others. Digital8 recordings can be made on standard-grade Video8 cassettes, but this practice is discouraged in the Sony user manuals, and Hi8 metal-particle cassettes are the recommended type for Digital8 recording. Most Hi8 tapes sold after the introduction of D8 are marked for both Hi8 and Digital8 usage.

History of multitrack recording

Multitrack recording of sound is the process in which sound and other electro-acoustic signals are captured on a recording medium such as magnetic tape, which is divided into two or more audio tracks that run parallel with each other. Because they are carried on the same medium, the tracks stay in perfect synchronisation, while allowing multiple sound sources to be recorded asynchronously. The first system for creating stereophonic sound (using telephone technology) was demonstrated by Clément Ader in Paris in 1881. The pallophotophone, invented by Charles A. Hoxie and first demonstrated in 1922, recorded optically on 35 mm film, and some versions used a format of as many as twelve tracks in parallel on each strip. The tracks were recorded one at a time in separate passes and were not intended for later mixdown or stereophony; as with later half-track and quarter-track monophonic tape recording, the multiple tracks simply multiplied the maximum recording time possible, greatly reducing cost and bulk. British EMI engineer Alan Blumlein patented systems for recording stereophonic sound and surround sound on disc and film in 1933. The history of modern multitrack audio recording using magnetic tape began in 1943 with the invention of stereo tape recording, which divided the recording head into two tracks.

The next major development in multitrack recording came in the mid-1950s, when the Ampex corporation devised the concept of 8-track recording, utilizing its "Sel-Sync" (Selective Synchronous) recording system, and sold the first such machine to musician Les Paul. However, for the next 35 years, multitrack audio recording technology was largely confined to specialist radio, TV and music recording studios, primarily because multitrack tape machines were both very large and very expensive - the first Ampex 8-track recorder, installed in Les Paul's home studio in 1957, cost a princely US$10,000 - roughly three times the US average yearly income in 1957, and equivalent to around $90,000 in 2016. However, this situation changed radically in 1979 with the introduction of the TASCAM Portastudio, which used the inexpensive compact audio cassette as the recording medium, making good-quality 4-track (and later 8-track) multitrack recording available to the average consumer for the first time. Ironically, by the time the Portastudio had become popular, electronics companies were already introducing digital audio recording systems, and by the 1990s, computer-based digital multitrack recording systems such as Pro Tools and Cubase were being adopted by the recording industry, and soon became standard. By the early 2000s, rapid advances in home computing and digital audio software were making digital multitrack audio recording systems available to the average consumer, and high-quality digital multitrack recording systems like GarageBand were being included as a standard feature on home computers.

Linear Tape-Open

Linear Tape-Open (LTO) is a magnetic tape data storage technology originally developed in the late 1990s as an open standards alternative to the proprietary magnetic tape formats that were available at the time. Hewlett Packard Enterprise, IBM, and Quantum control the LTO Consortium, which directs development and manages licensing and certification of media and mechanism manufacturers.

The standard form-factor of LTO technology goes by the name Ultrium, the original version of which was released in 2000 and can hold 100 GB of data in a cartridge. The eighth generation of LTO Ultrium was released in 2017 and can hold 12 TB in a cartridge of the same size.

Upon introduction, LTO Ultrium rapidly defined the super tape market segment and has consistently been the best-selling super tape format. LTO is widely used with small and large computer systems, especially for backup.

Videotape
Videodisc
Virtual
Video recorded to film

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