8 mm video format
Encyclopedia
The 8mm video format refers informally to three related videocassette formats for the NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...

 and PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...

/SECAM
SECAM
SECAM, also written SÉCAM , is an analog color television system first used in France....

 television systems. These are the original Video8 (analog recording
Analog recording
Analog recording is a technique used for the recording of analog signals which among many possibilities include audio frequency, analog audio and analog video information for later playback.Analog recording methods store signals as a continual wave in or on the media...

) format and its improved successor Hi8 (analog video
Analog video
Analog video is a video signal transferred by an analog signal. An analog color video signal contains luminance, brightness and chrominance of an analog television image...

 and analog audio but with provision for digital audio
Digital audio
Digital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...

), as well as a more recent digital recording
Digital recording
In digital recording, digital audio and digital video is directly recorded to a storage device as a stream of discrete numbers, representing the changes in air pressure for audio and chroma and luminance values for video through time, thus making an abstract template for the original sound or...

 format known as Digital8.

Their user base consisted mainly of amateur camcorder
Camcorder
A camcorder is an electronic device that combines a video camera and a video recorder into one unit. Equipment manufacturers do not seem to have strict guidelines for the term usage...

 users, although they also saw important use in the professional television production field.

In 1985, Sony
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....

 of Japan introduced the Handycam, one of the first Video8 cameras with commercial success. Much smaller than the competition's VHS
VHS
The Video Home System is a consumer-level analog recording videocassette standard developed by Victor Company of Japan ....

 and Betamax
Betamax
Betamax was a consumer-level analog videocassette magnetic tape recording format developed by Sony, released on May 10, 1975. The cassettes contain -wide videotape in a design similar to the earlier, professional wide, U-matic format...

 video cameras, Video8 became very popular in the consumer camcorder market.

Technical overview

The three formats (Video8, Hi8, and Digital8) are physically very similar, featuring both the same magnetic tape
Magnetic tape
Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...

 width and near-identical cassette shells, measuring 95 × 62.5 × 15 mm. This gives a measure of backward compatibility
Backward compatibility
In the context of telecommunications and computing, a device or technology is said to be backward or downward compatible if it can work with input generated by an older device...

 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
Betamax
Betamax was a consumer-level analog videocassette magnetic tape recording format developed by Sony, released on May 10, 1975. The cassettes contain -wide videotape in a design similar to the earlier, professional wide, U-matic format...

 format, using similar technology (including U-shaped tape loading) but in a smaller form factor in response to the small form factor VHS-C
VHS-C
VHS-C is the compact VHS videocassette format introduced in 1982 and used primarily for consumer-grade compact analog recording camcorders. The format is based on the same video tape as is used in VHS, and can be played back in a standard VHS VCR with an adapter...

 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
Pulse-code modulation
Pulse-code modulation is a method used to digitally represent sampled analog signals. It is the standard form for digital audio in computers and various Blu-ray, Compact Disc and DVD formats, as well as other uses such as digital telephone systems...

 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
DV
DV is a format for the digital recording and playing back of digital video. The DV codec was launched in 1995 with joint efforts of leading producers of video camcorders....

 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
Helical scan
Helical scan is a method of recording high bandwidth signals onto magnetic tape. It is used in reel-to-reel video tape recorders, video cassette recorders, digital audio tape recorders, and some computer tape drives....

 head drum to read from and write to the magnetic tape. 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.

Generations

Video8

Video8 was launched in the 1980s, into a market dominated by the VHS-C and Betamax formats.

In terms of video quality, Video8, VHS/VHS-C, and Beta-II offered similar performance in their "standard play" modes; all were rated at approximately 240 horizontal lines, depending on speed, quality of tape, and other factors. In terms of audio, Video8 generally outperformed its older rivals. Standard VHS and Beta audio was recorded along a narrow linear track at the edge of the tape, where it was 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
Frequency modulation
In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...

" (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 outperformed non-HiFi VHS/Beta.

Video8 had one major advantage over the full-size competition. Thanks to their compact-form factor, Video8 camcorders were small enough to hold in the palm of the user's hand. Such a feat was impossible with Betamax and VHS camcorders, which operated best on sturdy tripods or strong shoulders. Video8 also had an advantage in terms of time, because although VHS-C offered the same "palmcorder" size as Video8, the VHS-C tapes only held 40 minutes of tape (SP). Thus, Video8's 120-minute capacity served well for most users. (Both machines included longer playing modes at 120 and 240 minutes, respectively, but at the cost of reduced-quality images of only 220 lines resolution.) Longer sessions generally required additional infrastructure (AC power or more batteries), and hence longer recording times offered little advantage in a true travelling environment.

Video8/Hi8's main drawback was that tapes made with Video8 camcorders could not be played directly on VHS hardware. Although it was possible to transfer tapes (using the VCR to re-record the source video as it was played back by the camcorder), this inevitably led to degradation of the analog signal.

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
Digital video
Digital video is a type of digital recording system that works by using a digital rather than an analog video signal.The terms camera, video camera, and camcorder are used interchangeably in this article.- History :...

 formats, such as MiniDV and 8cm DVD
MiniDVD
MiniDVD is a DVD disc having 8 cm in diameter.The 8 cm optical disc format was originally used for music CD singles, hence the commonly used names CD single and miniCD...

.

Hi8

To counter the introduction of the Super-VHS
S-VHS
S-VHS is an improved version of the VHS standard for consumer-level analog recording videocassettes. It was introduced by JVC in Japan in April 1987 with the HR-S7000 VCR and certain overseas markets soon afterwards...

 format, Sony introduced Video Hi8 (short for high-band Video8). Like S-VHS, Hi8 used 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 420 horizontal TV/lines (560×480 in today's digital terms), a vast improvement from their respective base formats of 240 lines and roughly equal to laserdisc quality. Chroma resolution for both remained unchanged, at approximately 30 lines horizontal.

Both S-VHS and Hi8 retained the audio recording systems of their base formats; VHS HiFi Stereo outperformed Video8/Hi8 AFM, but remained restricted to high-end machines. In the late 1980s, digital (PCM) audio was introduced into some higher grade models of Hi8 (but never S-VHS) recorders. Hi8 PCM audio operated 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 could 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 offered 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.

Video8 equipment cannot play Hi8 recordings. All Hi8 equipment can record and play in the legacy Video8 format.

PCM Multi Audio

The Sony EV-S9000 (Hi8), Sony EV-S700U, and Pioneer VE-D77 (Video8) all supported a mode called "PCM Multi Audio Recording". While other 8mm decks supported stereo PCM recording, these units provided five additional stereo PCM tracks that were recorded in the video area of the signal. This allowed 8mm tapes to hold 6 "parallel" tracks of audio, each up to 4 hours long (in LP mode). Only one stereo track could be recorded or listened to at a time, and tracks were selected with the "PCM Multi Audio" selector button.

Digital8

Introduced in 1999, Digital8 is a form of the industry standard DV
DV
DV is a format for the digital recording and playing back of digital video. The DV codec was launched in 1995 with joint efforts of leading producers of video camcorders....

 codec
Codec
A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...

, 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 T-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 presently, 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 recording
Analog recording
Analog recording is a technique used for the recording of analog signals which among many possibilities include audio frequency, analog audio and analog video information for later playback.Analog recording methods store signals as a continual wave in or on the media...

s, although many models of Digital8 equipment are able to play Hi8/Video8 analog recordings.

Tape and recording protection

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
VHS-C
VHS-C is the compact VHS videocassette format introduced in 1982 and used primarily for consumer-grade compact analog recording camcorders. The format is based on the same video tape as is used in VHS, and can be played back in a standard VHS VCR with an adapter...

 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 is when the "door" is open and the "SAVE" position when it is closed. (Not all tape cases have markings for this information!) The tape can only be recorded on (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 to remove the write protection.

The home market

Efforts were made to expand Video8 from the camcorder market into mainstream home video. But as a replacement for full-size VCRs, Video8 failed. It lacked the long (5+ hours) recording time of both VHS and Betamax, offered no clear audio/video improvement, and cost more than equivalent full-size VCRs. Quite simply, there was no compelling reason to switch to Video8 for the home VCR 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 video 8mm Walkman
Walkman
Walkman is a Sony brand tradename originally used for portable audio cassette, and now used to market Sony's portable audio and video players as well as a line of Sony Ericsson mobile phones...

-branded players and recorders, with and without a flip-up screen meant for video playback and limited recording. These have been adapted for digital 8mm 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 remain in use on many airliners.

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 the professional ENG
Electronic news gathering
ENG is a broadcasting industry acronym which stands for electronic news gathering. It can mean anything from a lone broadcast journalist reporter taking a single professional video camera out to shoot a story, to an entire television crew taking a production truck or satellite truck on location...

/EFP
Electronic field production
Electronic field production is a television industry term referring to a video production which takes place in the field, outside of a formal television studio, in a practical location or special venue...

 field.

The future of the 8mm video formats

As of 2009, the popularity of the analogue 8mm formats has dwindled considerably and new camcorders that support the format are unobtainable having been superseded by the digital formats, mainly the MiniDV and 8 cm DVD formats. These in turn are being displaced by the high definition camcorders that record to memory cards. Both Video8 and Hi8 blank media remain widely available and affordable. Camcorders are still widely available in the second hand market.

The future of Digital 8 looks uncertain, though (as of December 2009) the Sony DCR-TRV270 remains available as an entry level camcorder. There are no known plans for a replacement model.

Dropouts

In Video8 and its successors, the smaller head drum and tape made 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' 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. Amongst 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 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.

Transferring 8mm footage to a computer for editing

Because Video8 and Hi8 are analog video formats, transferring either to a computer requires digitization
Digitizing
Digitizing or digitization is the representation of an object, image, sound, document or a signal by a discrete set of its points or samples. The result is called digital representation or, more specifically, a digital image, for the object, and digital form, for the signal...

. One method is to feed the video signal to an analog capture card
Expansion card
The expansion card in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard or backplane to add functionality to a computer system via the expansion bus.One edge of the expansion card holds the contacts that fit exactly into the slot...

 connected to the computer itself.

Another option involves the use of a pass-through adapter, which outputs a digitized video signal in the industry-standard DV
DV
DV is a format for the digital recording and playing back of digital video. The DV codec was launched in 1995 with joint efforts of leading producers of video camcorders....

 format. Many consumer-level MiniDV and Digital8 camcorders have this facility built in. The DV signal can then be fed into a computer equipped with a firewire port.

Another method is to use a Digital8 camcorder (with Video8/Hi8 playback; the Sony DCR-TRV330E for example) to transfer to a computer equipped with a firewire port. This is probably a better method due to the advantage of the computer having full control over the camcorder, which is impossible with analogue models.

A very simple method many people with miniDV cameras can use is feeding the a/v signal into the camera's a/v input jack after setting it up for "input" vs. "output." The signal can then be captured into the computer's video editing software (iMovie or Movie Maker). Only certain miniDV cameras provide the "a/v input" feature.

It should be noted that some Hi8 VCRs (including the Sony EV-S3000 and EV-S7000) had the option of adding digital noise reduction (DNR) by applying a digital comb filter. These VCRs also included a Time Base Corrector (TBC), which created a more stable image than playing through a camcorder. The resultant video image produced by using DNR and/or a TBC is different from playing through a Hi8 camcorder lacking these features. The effect of the playback device on the image quality may be a consideration for those transferring Hi8 footage to digital (i.e., a computer or MiniDV) for archival purposes.

Once on a computer, footage can be edited, processed, and transferred to DVD, the Internet, or back to tape. Many companies offer personal video digitization services.

The easiest method may be to take the tape and record it, via A/V cable, to a DVD at an appropriate speed (i.e. SP, LP, EP, etc.) and then use software and extract the DVD video data into a digital video file. However, the video signal will have been degraded by compression to MPEG2, whereas a transfer via a Digital8 camcorder's Firewire output will be in the higher quality DV format.

See also

  • Data8 – Data format for very similar media.
  • Ruvi
    Ruvi
    The Sony Ruvi was an analog video and still video camera released in 1998. The Ruvi was considerably smaller than any other camcorder available at the time, at 124 × 66 × 44.1 mm and 380g. This made the Ruvi small enough to keep inside a shirt pocket...

    – a unique camcorder based on Hi8 tape.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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