VideoPreservation Website

Chapter 9

VTR Interchangeability

The Variety of VTR Formats

Generally, all video cameras and monitors are basically interchangeable and will plug into any VTR and work. However, many VTRs are not interchangeable, which means that a videotape made on one type VTR will play back only on the same type of VTR. This lack of interchangeability is due to the different methods a particular VTR uses to record the various video, audio, and control tracks on the tape; the configuration of recording heads; and the speed and size of the tape.

The problem this creates is obvious. The compatibility of a tape made on a particular VTR should be considered before making the tape. Consider how much difficulty others will have when they try to play back the programs you make on your particular VTR. If they are not on the same format as you are, find out how expensive and difficult it will be to transfer your tape to the appropriate format. See Chapter 15—The Big Decision.

Each VTR is known by the size tape it uses. There are 5 different tape sizes:

2-inch, 1-inch, 3/4-inch, 1/2-inch and 1/4-inch

There are many different VTR formats within the various tape sizes. As we mentioned earlier, a 2-inch VTR is considered large-format whereas the term small-format refers to the 1-inch, 3/4-inch, 1/2-inch and 1/4-inch VTR sizes.

Another VTR category is TAPE CONFIGURATION which refers to packaging, such as reel-to-reel or open reel, videocassette, videocartridge, or videodisc. In order to avoid problems, it is essential to have some knowledge of the relative compatibility of the various VTR formats.

VTR Standardization

Five serious attempts have been made to standardize VTR formats:

1. The 2-inch quad format had to be standardized so tapes could be interchanged among Broadcast TV stations.

2. The 1-inch broadcast helical scan format was agreed to by Sony and Ampex in 1977 and called the TYPE C HELICAL SCAN VIDEO RECORDING format and is a compromise between the Ampex VPR and Sony BVH recording systems.

3. The 3/4-inch videocassette format (U-Matic) was standardized from the start by Sony.

4. The very widely used 3/4-inch EIAJ reel-to-reel format was established by the Electronics Industries Association of Japan in 1969. Unfortunately, several different 1/2-inch formats existed prior to the establishment of the EIAJ standard, but fortunately they have now become quite rare.

5. The -inch Beta 7 and 2-hour and VHS 2 and 4-hour home videocassette formats. These are 2 incompatible formats, but within each format there are many compatible machines produced by various manufacturers.

Unfortunately, manufacturers resist standardization because they feel it binds them longer to obsolete technology, but more standardization would sure make life easier for the video user.

Veteran video users have painfully accepted the fact that the manufacturers will always be changing formats on them without warning. The task then becomes how to use each format to its best advantage. There is no question that a variety of formats allows greater system flexibility and speeds technological advancements. New formats can be designed from the bottom up without having to conform to existing limitations.

Since all VTRs are electronically compatible, any videotape format can be copied to another format simply by plugging the 2 appropriate VTRs together and re-recording the program. In this manner, any tape can easily be transferred to whatever format is most expedient and economical for the user.

MAJOR VTR FORMATS

2-INCH REEL-TO-REEL VTRs Ampex AVR-3 (2-Inch Quad)

Super-good, outrageously expensive, and mammoth in size, a quad VTR generally is considered the best video recording and playback machine money can buy. An Ampex AV R -3 will run about $250,000 for a fully-loaded, signal-processed and image-enhanced machine. The quad's big advantage is its ability to go many generations (make copies of copies), perhaps 10 or 15, without significant quality loss.

However, ultra-sophisticated 1-inch and 2-inch helical scan systems are moving in fast for the kill. The quad is now a very endangered species. The TV networks are the major users of quads and will convert to 1-inch helical scan for most or all of their production and playback purposes in the near future because the quality of 1-inch helical scan is nearly comparable to quad for a fraction of the price.

IVC-9000 (2-Inch Helical Scan)

The IVC-9000 is a unique 2-inch helical scan VTR system that features quad-comparable performance with only half the tape consumption. Simpler than a quad but still much more expensive than 1-inch, the I VC-9000 offers a wide range of excellent and very sophisticated production and editing features. See Chapter 5—The VTR (I VC-9000).

1-INCH HELICAL SCAN—REEL-TO-REEL VTRs Ampex VPR-1 (Video Production Recorder)

The latest generation of sophisticated 1-inch VTRs, the VPR -1 is a high-performance high-band video recorder that can be purchased in a basic unit or upgraded to an entire system. The VPR-1 system includes AUTOMATIC SCAN TRACKING (AST), one-fifth speed broadcast slow motion, perfect still frame, manual jogging (movement of the VTR one frame at a time), real-time video verification (ability to monitor playback while recording), time base correction and more.

The VPR-1 sells for $20,000 to $60,000 and would be an excellent high-quality master production/editing VTR for a large industrial/educational TV system or for commercial broadcasting. It is compatible with other VPR-1 VTRs and also with the unique portable version, the VPR-20. Older Ampex VPR recorders can be retrofitted to the Type C broadcast format, and the newer machines that conform to the type C standard

are designated VPR-2.

IVC 1-Inch Systems

IVC has developed an excellent reputation for 1-inch VTRs over a period of many years, and because of the flexibility and dependability of the IVC system, it has since become the world's most widely used 1-inch format.

All IVC 1-inch VTRs have a 5,0 MHz bandwidth with 400 lines monochrome (b&w), and 300 lines color resolution. The 1/2-inch and 1/4-inch formats are limited to about 2.5 MHz and 250 lines in color. There are over 15,000 IVC-format video recorders in the field, and although the Company has developed several series of 1-inch VTRs over the years—the IVC-700, 800 and 900 series—it has made them all interchangeable.

Recently, IVC has introduced a new generation of 1-inch VTRs, the IVC-1070 ChromaCon 10, which features:

-High quality performance that "subjectively" equals quad high-band VTRs.

•The ability to produce a 5th generation tape copy that is clean, clear and crisp.

•Two professional quality audio channels, high reliability VTR design and simplified machine operation.

•An INSTANT VIDEO CONFIDENCE capability which allows monitoring the tape while recording and an improved motor drive and tape handling system.

Adaptors are available to convert other IVC series VTRs to record and play back ChromaCon 10 tapes.

Sony 1-Inch BVH-1000 and BVH-500

Sony Corporation is the worst offender in proliferation of VTR formats. So far, there have been 3 different Sony 1-inch formats alone; the older EV SERIES, the short-lived UV SERIES, and the more recent BVH broadcast 1-inch VTR format. However, all of these earlier machines have been dependable and have offered many useful features that the IVC and Ampex machines ignored at the time. For reliability, Sony models far exceeded all other 1-inch VTRs regardless of price. Yet, the EV and UV series VTRs did not have the high-quality performance of better Ampex and IVC finch VTRs.

Sony's BVH-1000 studio VTR and BVH-500 portable VTR (record only) are true high-band models designed specifically for broadcast applications. Older BVH recorders can be updated to the Type C standard broadcast 1-inch format, and newer machines are standardized.

The BV H-1000 Studio VTR features:

•A bandwidth of 4.2 MHz and a video signal-to-noise ratio of 48 db.

•A built-in bidirectional (B I DI RE X) tape search control that allows the tape to be reviewed in forward or reverse like a film editing table. I n the shuttle mode, the tape can be moved in either direction with coherent picture information from still and normal speed to over 60 times normal speed. This allows fast editing decisions to be made.

-Total editing control of 3 high quality audio tracks, including a CUE Channel which accepts SMPTE (tape address code) time-code information without internal modification. All tracks can he edited individually or simultaneously.

• 5 direct-coupled separate servo-motors and an advanced tape handling system.

- 2 concurrent digital tape timers perform a variety of record keeping and timing data.

• Easy to operate controls and advanced circuitry makes sophisticated adjustments easy for non-technical persons

-Modular design—VTR breaks down into 4 different components—tape transport section, operating control panel, electronics package and power supply. All 4 sections can he mounted separately.

Interfaces with the Sony BVT-1000 digital time base corrector, BVR 1000 remote control unit and BVG-1000 VITC (Vertical Interval Time Code generator/reader).

The BVH-1000 studio VTR is truly state-of-the-art video technology in a compact, reliable and sensible package.

Other 1-Inch VTR Formats

To further confuse the issue, several other companies offer noncompatible 1-inch VTRs. These include Bosch-Fernseh with its BCN SYSTEM, a USA version of which is marketed by IVC and called the IVC-8000 series. The BCN is a very reliable VTR and produces a quad comparable picture image. The IVC-8000 series includes the IVC8020, one of the few portable (44 lbs.) broadcast VTRs; the IVC-8040, a compact unit designed for mobile van use; and the modular designed IVC8050 studio VTR.

The standardized -inch videocassette is known as the U-MATIC FORMAT. Sophisticated UMatics are used by all major broadcasters and various models are found in most TV production studios. All -inch U-Matic videocassettes are interchangeable regardless of size and manufacturer.

Sony, Panasonic, Concord, JVC, Wollensac, N EC, Telemation, Teac and others all market compatible -inch videocassette units.

The U-Matic videocassette recorder (VCR) uses -inch Chromium Dioxide videotape in a 2-reel enclosed cassette, several times larger than the standard audiocassette. Advantages of the videocassette are: ease of handling, no threading, longer life, fewer dropouts, and stereo sound. All UMatic videocassette machines can play either b&w or color and have 2 sound tracks for stereo.

A vast range of -inch VCRs are available ranging from basic portable player-only machines to extremely sophisticated editing units with remote control and automatic editing control systems. A U-Matic VCR can be used for just about any application including broadcasting if used with the appropriate time base corrector.

1/2-INCH VIDEO FORMATS 1/2-Inch EIAJ—Reel-to-Reel VTRs

'/2-inch E IAJ reel-to-reel, "the old trailblazer," will live on as the format that really brought television into the hands of the people. More than any other piece of hardware, the 1/2-inch VTR is video. '/2-inch made video possible economically for the visionary masses.

A wide range of compatible VTRs is available in b&w, and color, portable, and studio configurations. The 1/2-inch format is the least expensive total production/editing video system.

The 1/2-Inch Videocartridge

The 1/2-inch videocartridge differs from the 3/4- inch videocassette in that the cartridge contains only one reel of tape, uses'/2-inch tape instead of 3/4-inch tape, and has only one sound track—no stereo potential as with the 3/4-inch cassette.

The significant advantage of the videocartridge is its ability to accept physically any 20- to 30- minute 1/2-inch EIAJ videotape. The tape must be wound onto a special self-threading cartridge reel and requires a plastic leader and a special cartridge playback VTR, but this means that any'/2-inch EIAJ tape, b&w or color, can also be used in a cartridge format.

This system combines the advantages of the VCR—such as easy threading, less wear on the tape, and ease of playback—with the already existing flexible system of 1/2-inch EIAJ reel-to-reel VTR s. Although now discontinued, cartridge units originally were slightly less expensive than 3/4-inch videocassette systems.

However, the cartridge systems, manufactured only by Panasonic and Hitachi, are limited to 30 minutes of record and playback time, whereas the 3/4-inch systems will record and play up to 60 minutes with standard tape and 90 minutes with extended-play tapes. Because of the U-Matic, the 1/2- inch cartridge never really got off the ground and has quietly been discontinued.

1/2-Inch Videocassette Systems

By 1976, video technology had evolved to the point where it could make a serious bid for the home. The 1/2-inch videocassette format was specifically intended for this purpose. Unfortunately, history seems to have repeated itself, because, as with 1/2-inch reel-to-reel, several odd 1/2-inch videocassette formats have inundated the marketplace before any standardization took place.

Most 1/2-inch videocassette recording systems share the same basic features:

• Easy connection to the VHF terminals of any standard TV set

• Easy cassette loading

- Built-in TV tuner, which allows you to watch one program on the TV set while the VCR is recording on another channel

• Accessory digital timers for automatic recording of TV programs and programmability

• Pause control to stop tape playback or eliminate commercials

• Inputs for external b&w or color video cameras and microphones •Audio dub control to add sound to previously recorded tape

• Instant replay and immediate playback of taped programs Built-in memory for returning to a specific point on the tape -Extended recording and playback times

Beta format-1, 2 and 3 hours VHS format-2, 4 and 6 hours

One-half inch videocassette systems have now become immensely popular. There are more Y2-inch systems in existence than all other video systems combined. By the end of 1980, there will be 2 million Y2-inch VCRs in American homes. These systems are either Beta or VHS format machines with VHS units making up the majority. Early in the evolution of 1/2-inch VCRs, there were several oddball formats such as the Sanyo V-Cord II and the Akai VT-300 and VT-350, but these soon went the way of other species that could not adapt readily to their environment.

Beta Format VCRs

There are three recording and playback modes within the Beta format, referred to as the X1, X2 and X3 modes, meaning that the VCR will record either 1 hour, 2 hours or 3 hours of material on the same length of tape. This is accomplished by changing the speed of the machine. The original Sony designed system, called the BETAMAX, was a 1-hour only recording and playback system. All Sony industrial VCRs use only this 1-hour X1 mode. Although the first Sony home VCRs were 1-hour only machines, they were followed later by a 2-hour mode, called BETA 2, and later by the extended play BETA 3 mode. Any VCR that has the Beta 3 mode also has the Beta 2 mode but not vice versa.

The resulting confusion from all these various Beta formats has been somewhat relieved by the newer line of Sony home VCRs — the SL-5400, SL-5600 and the SL-5800 which are able to record in the X2 and the extended play X3 mode as well as play back in all three Xl, X2 and X3 modes. This means these VCRs will play back any tapes made on any Beta format VCR. With better insight and planning, Sony could have eliminated some of this confusion.

The Beta 2 format has now become the standard home Beta format, and the Betamax 1-hour format has become the industrial Beta format. With both formats, there exists a very wide range of choice of machines and features. Within the industrial line, there is a portable VCR, several unique random access VCRs with automatic replay, search modes, solenoid controls and stereo sound. These industrial machines are able to interface with external programmable devices which allow sophisticated indexing, search and cue modes. Devices are also available for the industrial VCRs which allow interfacing with home computers and other microprocessors for interactive learning applications. Sony makes a device just for this purpose called a VIDEO RESPONDER which lets the user respond to questions presented by the videotape. The videotape in turn interacts with the user. Sony also has a very sophisticated Y2-inch editor VCR called the SLO-383. See pages 148-150.

The Beta 2-hour (X2) format is basically an extended version of theSony 60 minute Betamax system. Earlier Beta models had a 1 or 2-hour switch which in the 1-hour mode, allowed it to play back tapes recorded on the industrial Betamax VCRs. However, the 2-hour only Beta systems cannot play back tapes made on the 1-hour Betamax systems which effectively separates the 1-hour and 2-hour mode only Beta VCRs into two different incompatible formats. This is a big disadvantage for the Betamax/Beta format.

The Beta 2 VCR uses the same size cassette as the Betamax 1-hour system, but by halving the tape speed to a slow creep of 0.785 ips and reducing the track width proportionately, double playing time is achieved.

A wide range of choice is also available in the home line of Beta VCRs from several manufacturers. The Sony models SL-5400, SL-5600 and SL-5800 have the three-speed playback ability, automatic recording programmability and a wide range of variable playback and search modes. Many newer deluxe VCRs are able to fast forward the tape or move it ahead in slow motion one frame at a time with visible picture. Sony calls this feature BETA-SCAN. The SL-5800 employs a variable Beta-Scan control which allows the user to search at 5 to 20 times normal speed in forward or reverse Shuttle Mode Search).

Toshiba, who also uses the Beta format, has a SUPER-SCAN mode which moves the tape at 40 times normal speed in forward and reverse with visible picture. This fast search ability is useful when using the long play mode recordings and quick Location of a particular tape segment is desired. Sony has a remote control device called the BETASCAN REMOTE COMMANDER to control all the variable speeds and play modes.

Toshiba, Zenith and Sanyo are the other major distributors of Beta format VCRs. All newer Beta VCRs will record and playback in the 2-hour X2 and 3-hour X3 modes. The Zenith machines are nearly identical to the Sonys, but Sanyo and Toshiba make their own versions. As we mentioned, the Toshiba models have the Super-Scan feature but they also have the nice electronic push-button solenoid controls, electronic tuning and 7-day programmability. A remote control is also available,

Like Toshiba, Sanyo has several models with scanning options, remote controls, solenoid control and programmability. Only the Sony models, though, allow the 3-speed playback. This feature is only relevent if you intend to play back tapes made on the industrial Beta machines or have old 1-hour Beta programs. All prerecorded Beta tapes are made in the 2-hour X2 mode.

Portable Video Recorders

Both Sony and Toshiba have battery powered portable Beta home VCRs and color cameras. These cameras can also be used with any of the deck-type models by using an adapter which is included with the camera. The newer generation of cameras by Toshiba and Sony are very lightweight, easy to use and take excellent pictures in very low-light situations. For making first generation tapes that will not have to undergo serious editing and duplication, the 1/2- inch systems are really ideal and very cost effective relative to any other videotape format,

The Beta 2 system is intended primarily for home off-the-air recording, home recording with a camera and microphone and playback of mass marketed pre-recorded tapes. Fotomat Corporation will convert 8mm and super 8 home movies to Beta format cassettes for about S3 per roll of 50 ft. film. They will also transfer 35mm and I nstamatic slides to tape and add a fast lap dissolve between slides. Other companies such as S/T Videocassette Corp., 500 Willow Tree Rd., Leonia, N.J. 07605 (Family Vision) offer similar services

The VHS Format

On the other side, though, is a very imposing array of video and TV chieftans committed to the VHS format, originally developed by JVC (Japanese Victor Corporation). At least 14 electronic manufacturers and distributors are firmly behind the VHS system, and these include MGA (Matsushita), JVC, Sharp, Hitachi, RCA, GE, Sylvania, Panasonic, Quasar and others.

The VHS machine is capable of recording and playing up to 6 hours on a single tape, and most newer models offer all three 2, 4 and 6-hour modes. The extended play modes have been achieved by further slowing the tape by half and narrowing the recording head gap and video track. Obviously, picture quality will be sacrificed in the multiple play and extended play modes, but some of this quality loss is offset by internal noise reduction circuitry and direct drive motors.

The battle of the giants has been under way for some time now over the market for 1/2-inch videocassette systems. On one side of the great home video battlefield we find the powerful coalition of Sony,Toshiba, Sanyo and Zenith who offer the Beta system. As we mentioned, the Beta system offers a wide range of options, equipment and accessories.

This brings us to a very important point. Any VCR that has more than one speed of operation must make sacrifices in picture quality because the video heads cannot be optimized for more than one mode of operation. Therefore, a 2-hour only VCR will have better picture quality than a 2/4 or 2/4/6-hour mode VCR if you compare the 2-hour mode in each one. The one way around this problem is to use only one set of video heads for each speed mode. JVC does just this with its 4-head HR-6700 VCR. It is a 2 and 6-hour machine and is generally recognized to be one of the best quality VHS machines. Because single speed VCRs afford the best recording quality, all VHS and Beta industrial VCRs have only the single speed mode.

On the home front, VHS systems have lots of goodies too, such as integrated digital LED timers, electronic TV tuners, 7 to 14 day programmability, solenoid controls, high-speed search, variable speed shuttle in forward and reverse with picture, still frame viewing, audio dub, remote control, automatic program locating functions and many other features. A wide range of super lightweight portable VCRs (12-14 lbs.) and cameras (4-6 lbs.) are offered by most VHS manufacturers. Retail prices of VHS systems are competitive with Beta systems and range from $700 to $1,400 for VCRs and from $600 to $1,400 for color cameras.

Like the Beta format, the VHS system provides an extremely wide range of choice between manufacturer's features and accessories. Like Beta, there is a line of industrial VCRs made by Panasonic which includes solenoid operated player and recorder models with stereo sound, random access and editing capability. Very lightweight portable models are also available as is a wide range of good low cost cameras. See page 153,

Which Format Is Best?

Well, this is a difficult question. There are many videophiles who are forever devoted to each format and claim one format or the other to be superior. Generally speaking, the faster tapes of the Beta format should offer better quality. The Beta tape threading system also places less wear on the tape and has other advantages. See page 146. However, VHS offers excellent picture quality, longer recording times and complete interchangeability because all VHS machines have a compatible 2-hour mode. VHS VCRs also afford a great diversity of sophisticated features. VHS portable VCRs are the lightest, and portable systems such as the JVC HR-2200 feature very high quality pictures, clean edits, variable speed shuttle search modes and an 11-function remote control.

Perhaps the big deciding factor is your ability to trade tapes with others. VHS clearly has the edge here as 70% of the home video recorders are VHS format machines. Most special interest video networks are being established with the VHS format and, generally, if someone distributes'/2-inch tapes, it is in the VHS format. Beta, however, is quite widespread in industrial video networks. Either format is very good and affords many options, but the VHS forces may become the dominant influence in the '/2-inch video world.

How To Insure Maximum Compatibility

Interchangeability between 3/4-inch and 1/2-inch compatible formats is superior to most reel-to-reel formats. One-half inch videocassette recorders have less interchangeability problems than -inch cassettes. This is due to a number of factors. Mainly, the video tracks on the '/2-inch VHS and Beta formats are very short, which decreases the possibility of errors resulting from

tape shrinkage and expansion. Longer tracks on -inch and 1/2-inch El AJ reel-to-reel tapes increase the possibilities for tracking and alignment problems. Cassettes also keep the tape cleaner, and eliminate threading errors. The internal works of the machines are hidden from mischievous hands and this helps too.

Insuring videotape interchangeability is a difficult and precise business which requires strict manufacturing standards. These standards often are not perfectly adhered to by the manufacturers, and there are subtle differences between individual VTRs which hinder true tape interchangeability. These differences include such factors as variations in tape tension (skew) between different manufacturer's VTRs and head drum surface coatings that affect tape playback. Of course, any improper variation in tape path or head alignment on a VTR will seriously hinder tape interchangeability. Heavy VTR users who require that their machines work at optimum levels should check the tape alignment (tracking) and tension (skew) routinely with a factory standard tape (available from the VTR manufacturer) and a tension gauge (available from Tentel Corp), see Chapter 14—Maintenance.

Any VCR, though, can get out of alignment. The heads can become clogged and other problems may arise, especially if moving the machine often or subjecting it to hostile environments. All VCRs should be checked and cleaned by a competent video service facility, and replacement of vital parts every 1200 or 1500 hours of use should be made. This can be expensive ($100-S400), so investigate an extended warranty program from your dealer if you anticipate extremely heavy use.

Overview

As you can see, there is a wide range of VTR formats to fill all your needs, provided you have the dollars. If just starting in video, you can select whatever format is best suited to your level of technical competence and programming needs. If you've inherited a conglomeration of incompatible VTRs, first try to define which VTRs are best for recording, which ones can be used for dubbing, and which ones will become boat anchors or decorative rock garden pieces.

Once you have taken the inventory of salvageable equipment and issued the obituaries for those older VTRs that must make The Great Video Transition, you then can go out and spend your money on sparkling exotic new video technology.

Think Before You Spend

Older VT Rs are "free" but they may not do the job well enough and that may cost you money. New video technology may represent a considerable capital risk. Think out any sizable investment in video equipment carefully. Do you really need 2 sophisticated editing VCRs when you could get

by with one new editor and use one of your present videocassette units as a playback machine? Could you make do with some of your other equipment for most of your present applications and just rent the high-priced gear when you need it for a big job with a big budget?

Remember, too, that videotape can be copied from other formats and time base corrected, image-enhanced and noise-reduced. N ow, image processing technology is at the point where tapes can have their total picture quality substantially improved by certain processing techniques. Of course, this can be expensive. Without sophisticated processing technologies, some quality loss will result and transfers may incur additional costs and present extra problems.

These are questions that deserve research on your part when you contemplate purchasing video equipment. For more thoughts on the matter, see Chapter 15—The Big Decision.

Having surveyed the variety of specific VTR formats, we will now get our "hands on" some basic VTR equipment.

Up to this point we have examined the wide variety of available video equipment and how it might be commonly used.

Next, we will treat the specific features and operational procedures of the most commonly used VTRs and VCRs.