Questioning Technology: Lost Memories
This holiday season millions of camcorders will whir away in American homes recording family memories for posterity. Posterity? Are you kidding? How about a few years, if you are lucky! It's one of the touchiest questions in video and audio and few amateurs bother to ask it: How long does recording tape last? Most of us operate on the assumption that the tapes we record today will playback far into the future. But how long can we expect that tape to reliably store and recall our video and audio memories? The answer is not found in tape advertisements. But the truth is, unfortunately, that tape, whether it be for video, sound or computer data, is not forever. Unlike movie film -- which can last for decades -- magnetic recording tape is far more fragile. In fact, no magnetic recording medium is permanent. Those ribbons of cobalt ferric oxide or metallic particles inside the plastic shell of a video or audio cassette represent relatively new technology. Even professionals have had only about 25 years of experience with traditional oxide video tapes, and the newer metal tape, introduced with the Video 8 format in 1985, is still an infant. So, how long does a videocassette last? Traditionally, tape manufacturers have waffled on the question. Consumers have been offered some general storage tips (like donÕt leave a cassette on a car seat in the summer sun) and assurances that the subject is not a matter for serious concern. But one leading video tape manufacturer, Sony, has gone on the record with a specific estimate on the life expectancy of its video tape products that should shatter any illusions that video is forever. Sony's research, which applies to both consumer and professional grades of video tape, was conducted in Japan with the company's broadcast Betacam system, the only video recording format that can use either oxide or metal tape formulations. One of the purposes of the study, Sony noted, was to compare the longevity of the newer metal tape against traditional oxide formulations. The durability of both types of tape (which covers the spectrum from brand name bargain tapes sold in supermarkets to high performance premium cassettes) was extensively tested by Sony in environmental chambers at varying temperature and humidity levels. The researchers wanted to find out how environmental conditions affected key performance parameters. In order to see how wear and tear affected tape, Sony ran cassettes through 500 playback and rewind cycles at a slow 1/30 speed on a VCR. The results, according to the Sony study, is that both metal and oxide tape, when stored under environmental conditions of 77 degrees F and at 50% relative humidity "are very stable and have no change in video electromagnetic performance." The Sony report concluded that the life expectancy of any tape depends on disintegration of it's chemical components, such as plastic base film, binder polymers, back-coating materials and lubricants. Heat and moisture accelerate the breakdown of these organic materials in all tape formulations, the report said. So what's the bottom line. How long does Sony tell us we can expect a videocassette to last? Since environmental conditions are the key to the tape's chemical stability, the answer is based on storage conditions. If the user keeps tapes at a constant temperature between 59 degrees and 77 degrees F and at a relative humidity level of 40 to 60 percent, Sony predicts all modern tape formulations will last 15 years without significant degradation. It is important here to note the word "constant" when speaking of the environmental conditions in which tapes are stored. Sony recommends there be little fluctuation in temperature or humidity to prevent expansion and contraction of the base film. Since most of us don't occupy such ideal temperature and humidity-controlled environments at home, the 15 year figure is unrealistic for the average person. For important, irreplaceable tapes, Sony tape product manager Les Burger recommends that consumers follow the practice of many professional video producers and make protection copies from the master tape every three to five years. These copies, though down a generation, at least provide insurance against any deterioration or failure of the original master. Burger also recommends winding important tapes at least one a year. When a tape is so valuable that money is no object for its protection, the ultimate in archival preservation is to make a digital backup copy at a professional video facility. By copying a VHS or Video 8 tape to a professional digital format, there will be virtually no loss of image quality when future copies are made. But be prepared for to pay several hundred dollars for this protection. In the audio world, the same problems apply. This is especially true for home studio musicians who commonly use the inexpensive DAT (digital audio tape) cassette format for music mastering. At a recent Audio Engineering Society seminar in New York City, a group of the nation's top media archivists and recording engineers sounded an alarm concerning false assumptions about the permanence of recording tapes, especially DAT. Veteran recording engineer and multiple Grammy winner Roger Nichols warned musicians to treat the DAT format as a temporary medium and to move their recordings to a more stable format within a year. "When you are worried about longevity the DAT tape isn't quite going to make it," he said. Ironically, the problem of disappearing information on magnetic tape is not limited to amateurs. One of the most passionate pleas at the audio session came from Marc Kirkeby, senior director of the American music archives for Sony, a company that is not only a leading manufacturer of digital recording equipment and media, but the owner of more than 600,000 recordings dating back to the turn of the century. "The potential for disaster out there cannot be overemphasized," said Kirkeby, who noted that many vintage commercial recordings by top artists are retrievable today only through blind luck. "We have tapes from 1949 that sound wonderful," he said. "We have tapes from 1989 that are shot to hell. And it's all just chance." There are valuable analog master tapes from major 1960s recording artists that will be lost within the next decade, Kirkeby predicted. "We had the master of the first Janis Joplin Big Brother album in (at Sony Music Studios) for something a couple of weeks ago and in plenty of places you can see right through it. The shedding (of the magnetic coating) has progressed to the point of total clarity." This holiday season, when a friend or family member comments that they are video taping or recording an event for future generations to enjoy, set them straight. Video tape is not forever. Audio tape is not forever. Magnetic media must be handled with care, stored properly and copied to new media every few years. Such knowledge can save a lot of disappointment down the road.