Videotape Analysis and Evaluation

Roosa, Mark. (1998) "Videotape Analysis and Evaluation." In Playback: A Preservation Primer for Video (San Francisco, Calif.: Bay Area Video Coalition, 1998): 5-17.

Mark Roosa has written about preservation issues in audio and video since the early 1990s. His essay on analyzing and evaluating videotape was very succinct and comprehensible. Roosa talked about three major areas: 1) the physical properties of videotape; 2) the factors that lead to tape deterioration; and 3) how to identify signs of deterioration.

As I've mentioned before (in this and the Audio Preservation blog I keep), magnetic tape is made up of three major portions: magnetic particles, binder, and backing. The magnetic particles carry the signal of the audio and video; but they are suspended on the binder layer. And it is the chemical makeup of the binder that influences uniformity, the specific arrangement, and how well the particles stick to the binder. The backing is polyester (PET), and the most chemically inert. Videotape is generally very thin, only .5 mil; so it suscepticle to streching, breaking, and print-through.

Because most libraries and archives do not have the funds to do comprehensive restoration programs for video, preventive measures must be taken to maximize the media's life expectancy of each item. Some of the general preservation principles I've learned about storage and handling, stable and consistent environmental controls, and isopermic theory apply here.

He also talked about how to identify problems with videotape. There's two ways of doing that: 1) visual inspection; and 2) playback. Of course it's easier to tell problems visually when you can view the tape pack. That's not the case with videocassettes. If your tape is safe enough to play, Roosa identifies some potential problems you should note when doing a survey of videotapes:

* Video noise
* Blips
* Color shift and distribution
* Image and audio distortions

There were also some important notes in Playback's introduction by Sally Jo Fifer and Luke Hones. They talked more generally about why it's so important to be concerned about the longevity of videotape. The media arts field is awash in materials like video art and experimental video. They make an important point that television stations and film studios have much more of the monetary resources to preserve their property in a way that individual artists and non-profit organizations can't.

Video is also an important tool in documenting the performing arts, as well as oral history. For visual artists, works can't be considered complete unless all aspects of that installation are intact. It's important to remember that it's not just the videotape that's in danger; but the playback technology itself. The example they give is the television monitor that is used in the installation. The problem: the television which can't work unless obsolete tubes are replaced. Pure market forces in play here. Wow--when the artist includes the technology as part of the work; what hope is there for preserving it?