FREQUENTLY ASKED QUESTIONS
A: No. All magnetic recording is done by “imprinting” either a North or South polarity on a large number of individual magnetic particles in a pattern. Once the polarity in the particles is changed by either erasure or a new recording, there is no known method of determining the previous polarity. Any recording that has been erased or recorded over is gone. In very rare occasions, the erasure or new recording can miss some of the old recording and small fragments are left. Trying to capture anything from these tapes is very expensive, usually does not work and, at best, can recover only a few very fragmented sounds or images.
Q: If I don't copy my old tapes right away am I likely to lose them in a few years?
A: Unfortunately, the most likely answer is: yes. Experts have developed a variety of very effective methods of restoring old tapes but tape deterioration is becoming more severe over time. In addition, the technology to play old tapes is disappearing at an alarming rate. New tape machinery is not being made, parts to fix older machines are becoming unavailable and the people who know how to use and fix tape machinery are retiring from the work force. No one really knows just how soon it will happen but the ability to play old tapes is disappearing.
Q: How long can I expect my tape to last?
A: The variables involved in this question are so numerous that no single answer can possibly be correct. From a tape viewpoint, however, as a general guideline:
- If you have professional quality tape from a major manufacturer and keep it in a dry environment that is comfortable for you, it should last at least ten years.
- If you keep tape in a stable, controlled environment that is slightly too cold and too dry for a person to be comfortable in, your tape should last for at least fifty years.
- If tape is of a totally unknown brand or is miniaturized there is no real life expectancy: consider yourself lucky every time it still works!
- Some rare types of tape already cannot be played since no working machinery exists.
- Many experts predict most tape types will be difficult to find working machinery for after the year 2025, but no one really knows.
- Even if you find working machinery, tape must be in “good” condition to play on the machinery. To help protect your tapes, you should store them in a proper environment.
Q: At what temperature and humidity is it best to store my tapes?
A: It depends on which is most important to you -- long tape life or easy access. The colder and drier the environment in which you store your tapes (until you approach a lower limit of about 45 degrees and 20% RH), the better for the tapes, but the less convenient for you. Tapes stored at low temperatures and humidity cannot be used safely until they are returned to near-operating conditions in a controlled environment. This requires special handling and a lot of time.
Q: Why do my old tapes stick or squeal when I try to play them?
A: The most probable cause is binder hydrolysis. This is a chemical breakdown of the tape, usually due to interaction with moisture in the air over a period of time. The result is a sticky residue on the surface of the tape. For this reason, the problem is often referred to as “sticky shed”. The problem occurs because the tape has been stored in an area that is too damp and too warm. Tapes with binder hydrolysis can usually be fixed.
Q: Do my old tapes need to be cleaned before being copied?
A: If there is any evidence of dust, debris or damage on your tapes they should be cleaned. Testing by both manufacturers and government labs shows that very small particles on the surface of a tape can interfere with the signal during copying. Cleaning by a professional can also identify serious tape problems that, left untreated, may cause permanent damage during playback.
Q: Are the new digital tapes less subject to disasters than the old analog formats?
A: No! The new tapes are much more delicate. The smaller size, higher recording density and new metal particle formulations make modern tape formats much more susceptible to disasters. SPECS BROS. has developed special techniques to deal with these problems.
Q: If I have a disaster at home can my personal collection be restored?
A: Recovery techniques used on professional tapes can also be used on most consumer formats. However, some techniques do not work as well on miniaturized tapes, such as 8mm or Mini-DV video. If your tapes are easily replaced store-bought copies, it is often less expensive to replace the tapes than to pay for professional restoration.
Q: My tapes got wet. What should I do?
A: Wet tapes often require decontamination. Improper drying causes tapes to deform, break, stick together, and may increase chemical decay. Get your wet tapes to a restoration specialist fast.
Q: Can wet tapes be "freeze-dried" like some paper materials?
A: Freeze-drying has been used on tapes but it is not recommended. Certain chemical components of tape are damaged at freezing temperatures. The procedure can also leave dried contaminants, which interfere with playback, on the tape surface.
Q: There's fungus growing on my tapes. What should I do?
A: Do not play tapes with fungus! This can damage the tapes, contaminate your machine and may even throw enough spores into the air to affect you. Fungus can be removed but this is not something you should try yourself. If you find fungus on a tape, isolate the tape to avoid spreading contamination and call a specialist. Also examine the area where the tapes are stored: it is probably too humid.
Q: What does "exercising" tapes mean and do my tapes need it?
A: "Exercising" is the periodic winding and rewinding of tapes. It is recommended to reduce print-through, an "echo" effect that occurs on analog audio tapes in storage. If you have analog audio tapes, it can be important to exercise your tapes on a regular basis. Exercising has not been shown to have a beneficial effect on any other type of tape.
Commercial videotape use started in 1956 in the form of 2-inch quad tape, used in Australia from 1958 to 1985. In a little over 40 years, more than 50 formats have been introduced world wide, each relying on the same fundamental process of recording image and sound data onto magnetic tape.
U-Matic (in common lingo ’3/4’ after the tape width in inches) is a format developed by Sony. It has three different versions: LowBand (LB), HighBand (HB) and Special Performance (SP), which differ by the subcarrier frequencies used for luminance and chrominance recording. U-Matic LB has been around from the early 1970s and is one of the oldest cassette video formats. HB has increased chroma subcarrier frequency, which improves colour resolution. In the SP variant, both chroma and luma subcarrier frequencies have been increased. U-Matic SP is still occasionally used as a production format for those not wealthy enough to use Beta SP or similar.
Although U-Matic does not appear much better than Super VHS on paper, the higher colour resolution and much better signal-to-noise ratio make the picture subjectively far more enjoyable. The U-Matic tape transport is also much faster in changing modes, which makes editing less frustrating. LB and HB U-Matic tapes were often used for archiving because of the relatively low tape costs and low recording density, which makes the tapes robust against aging.
In the early 1980s Sony introduced the semi-backward-compatible high band or BVU (Broadcast Video U-Matic) format, and the ‘original’ U-Matic format became known as low-band. This high-band format had an improved colour recording system and lower noise levels. The introduction of ENG (electronic news gathering) using the BVU platform for news and production brought instant results, unlike the film processes used to date. The expense and time limitations saw the end of using 16mm film for this everyday purpose.
1” SMPTE Type C Format
These machines use 1” tape in open reels. The main advantages are very fast transports and low recording density, which makes the format rather immune to drop-outs. Tape costs are high. The units can record single frames, which made them popular in early computer animation. Some units with vacuum capstans could operate from stop to nominal speed within one video field. The tape makes almost a full circle around the picture drum, and a single head is able to record and playback the entire video signal (short of a few lines right after vertical sync). Most other video formats have at least two picture heads, which alternate between fields. This format is now becoming obsolete. Note that in C format, the entire composite video signal is recorded and played back as is, without splitting it to Y/C, like most composite recorders do, or limiting the bandwidth in any way. The main manufacturers include Sony, Ampex and BTS.
1” SMPTE Type B Format
Similar to C format, but uses segmented helical scan. The diameter of the picture drum is small, and a single video field is recorded in six separate tracks. B format does not allow for many special modes – play, FF and REW are just about it. Manufactured by Bosch.
Developed by Sony, perhaps the most popular format for both field acquisition and post production today. Betacam uses cassettes and transports similar to the old Betamax home video format, but the similarities end there. Tape speed is six times higher, and luminance and chrominance are recorded on two separate tracks. The two colour difference signals are compressed in time by two and recorded sequentially on a single track.
Digital successor to the venerable Betacam SP format. Introduced by Sony in 1993, uses physically similar half-inch cassettes. Camcorders with 40-minute capacity are available, making Digital Betacam the first component video digital ENG (electronic news gathering) format. Digital Betacam units play back, but do not record analogue Beta SP tapes.
DV (formerly DVC) is a format being backed by manufacturers such as Sony, Philips, Thomson, Hitachi, Matsushita (Panasonic) and others. It was the first digital recording format in the reach of consumer markets. As a curiosity, the consumer version (DV) sports one of the densest recording techniques based on magnetic tape media – more than 0.4 megabits per square millimeter. DVCPRO is a professional variant of the DV by Panasonic. The only major difference is doubled tape speed, which is needed for better drop-out tolerance and general recording robustness. It is also capable of 4x normal speed playback. DVCAM on the other hand is Sony’s variation of the theme, sitting somewhere between DV and DVCPRO. Tape speed and track width have been increased, but not as much as for DVCPRO. Furthermore, it uses the same metal evaporated tape as DV, while DVCPRO uses metal particle tape.