Week's Reading: Preservation

Preservation: Why Are Films And Videos Disappearing?


Nitrate Films

Nitrate-base film stock, in theatrical use until 1951, is hazardous to store and decays even in controlled archival storage. No way has been found to prevent the self-destruction process to which every foot of nitrate eventually will succumb. And there is no mistaking the end result. The film surface becomes sticky, and the image shifts and fades beyond recall as the celluloid itself turns first into a coagulate and finally into brown powder. In the final stage of decomposition, the flashpoint is lower than that of newsprint and, because the gases given off by the decomposing nitrate can build up pressure, spontaneous combustion is possible.

The technology for archival preservation has existed for more than 30 years, but the work remaining to copy nitrate films onto modern acetate "safety" stock is enormous. American archives presently hold approximately 105 million feet of nitrate film (of the unique or best surviving material on a title) which will take 15 years to preserve at the present rate of copying. Nitrate holdings awaiting preservation in private and corporate hands, including newsreels, major studio collections, American films in foreign archives, and independent productions, are estimated to be equal to that currently awaiting copying in the archives.

Color Films

Virtually all current production for film and television today consists of color film in single strip emulsion. It has been learned from bitter experience that, unlike the earlier three-strip Technicolor process, today's color film can fade irretrievably in as little as five years. The gradual shifting of color values can advance quickly to a point at which the original release quality cannot be recovered without making compromises in contrast, definition, and overall image quality.

Unlike the problem of preserving nitrate films, where the method of preservation is well known, there is no practical solution for preserving the color in single strip emulsion safety film. There are a number of possibilities, including improved, longer-lasting film emulsions, laser holographic techniques, videodisc, and digital storage, but they require further research and development.

The only way to preserve color images is to generate three black-and-white records of each of the primary colors. But the cost for this easily can be $40,000 per feature-length film, plus subsequent charges for storage, maintenance, and the retrieval of a recombined, correctly registered color image from the separations.

At present, the only cost-effective means of dealing with color fading is to slow it down by storing color films in vaults designed to maintain below freezing temperatures and low humidity. This is a stop-gap measure, however, and while cold storage may prolong the life of color films, it cannot ensure their survival until the time when it may be possible to transfer the images onto an archivally stable medium.



The "Vinegar" Syndrome

As early as 1912 safety (non-flammable) film stock was developed for non-theatrical use. This "diacetate" safety film was used extensively in educational, religious, and amateur films, and often gives off an odor of camphor.

Modern safety film bases usually are composed either of acetyl cellulose (triacetate) or polyester (product names "Estar" or "Cronar"). When exposed to a flame, modern safety film will curl and extinguish itself. When properly stored over the course of its lifetime, safety film should not decompose over time and is estimated to have a shelf life as long as that for good quality paper, approximately 200 to 300 years. Proper storage will also minimize shrinkage and brittleness in the film.

It is important to note, however, that during the past several years, archivists and technical experts have learned that triacetate film is not always as stable as was once believed. In a number of collections, acetate degradation has been identified as a new and potentially serious problem for preservationists. Commonly referred to as the "vinegar syndrome" (because of the strong vinegar-like odor given off by deteriorating acetate), acetate degradation proceeds in a way not dissimilar to nitrate deterioration, although without the flammability factor. The problem has proven to be especially serious in films improperly stored in high temperature and humidity environments, where many aspects of deterioration--loss of plasticizer from the base causing curling, buckling, shrinkage, and brittleness--are clearly accelerated. It is also believed that the problem is contagious, and that degrading acetate films can infect other films stored in the same area.

The most common gauges on safety stock are 70mm, 35mm, 16mm, 8mm, Super-8mm, and a number of early gauges which utilized diacetate safety including 9.5mm, 22mm, 28mm, and some 17.5mm (positives only.)

Television & Video Tape

At the four major television networks, there are an estimated 100,000 television programs. Combined with the holdings of the major television archives and syndicators, as many as 200,000 hours of television are being safeguarded.

Much of the early 1940s and 1950s live television programming is lost for the simple reason that it was never recorded on any medium. Until the late 1950s and early 1960s, television shows were mastered onto films or were recorded onto kinescopes (photographed onto film directly from television screens during broadcast). Such programs can be preserved as films. Videotape came into use in the late 1950s as a means of recording television shows. The survival rate for programs recorded on tape -- and even today's broadcasting -- may be as low as that for the very early years of television, since attempts at preservation are hampered by a lack of knowledge concerning the useable life of videotape.

Estimates of the shelf life of videotape range from as low as 5 to 20 years, to as high as 100 or more years, An enormous amount of television programming survives only on videotape. However, since tapes are erasable for re-use, economic rather than archival considerations can often dictate the survival of any given program.

One more significant problem for television preservation concerns equipment. Because of the rapid development of videotape technology, equipment to record and play back tapes has often become obsolete. Formats -- such as the half-inch reel-to-reel portable machines of the late 1960s and early 1970s -- are no longer in use today. As a result, the work of many independent video artists, as well as anthropologists or sociologists, is endangered because the equipment needed to preserve their works is frighteningly scarce. This is equally true for a widely-used format such as two-inch broadcast tape. Thus, for television preservation, there is a need to preserve equipment as well as programming to ensure that the images may be retrieved and viewed in the future.

To address the area of videotape preservation, the Center has initiated a number of projects. These have included the two-year "National Moratorium on the Disposal of Television Programming," initiated in 1986, and the preparation of comprehensive national guidelines for "The Selection of Television Programs for Retention and Preservation." These selection guidelines were distributed to the nation's television networks, broadcast groups and production companies in 1988.

In 1987, the Center organized the first national conference for local television news archives, the largest and fastest growing constituency in the moving image archival field today. In 1990 it completed the negotiation of an agreement between Capital Cities/ABC Inc., the UCLA Film and Television Archive, and the Museum of Television and Radio that facilitated the donation of the history of ABC's entertainment programming -- over 20,000 programs from 1950 to 1980 -- to the national collection. Currently, the Center is overseeing a federally-funded grant project to write and publish a basic curatorial manual covering all aspects involved in the administration of television newsfilm and videotape collections.