Librarians and Older Technology Part 3: Moving Images

September 17, 2019

Older formats of photography, sound, and moving images are often stored in archives, historical societies, and records centers, as discussed in my first post about skills for special librarians and obsolete technologies. Unfortunately, moving images often end up in collections without much documentation or even provenance.

They are part of marketing and promotion for corporations and institutions. They document events that affected the institution or residents of the area. Or, they are the work of a corporation or individual from the community. Moving images can be found within a collection or record group; the reels might be stored separately on the shelf, or in cabinets and drawers

Once located, follow standard professional procedures while evaluating the physical materials for the collection.

    • Identify the format.
    • Identify the content.
    • Locate appropriate playback equipment.
    • Determine whether the content fits within the mission and collecting policies.
    • Confirm that the media are stable enough to play and to copy or reformat.
    • Evaluate for reformatting or digitization for public access.

Moving Images or Film

Moving images are as difficult to work with as recorded sound. Moving images are found in two or three basic formats: film-based, magnetic, and digital. As with recorded sound, the content varies as do the structure and stability of the formats.

Historical background

Moving images are a subset of photography or still images. Projection equipment and motion picture cameras were developed by Thomas Alva Edison, among others, in early 1880, while the film was marketed by George Eastman beginning in 1885.

Moving images were shot and developed on a variety of flexible film stock including nitrate, cellulose acetate or safety film, and polyester. Highly flammable nitrate film was superseded by cellulous acetate film or safety film (developed in 1908) by the early 1930s. Safety film is actually printed along the edge of the film to differentiate it from nitrate. By the 1960s and 70s, acetate film was replaced by polyester film.

Moving images evolved from images embedded in the emulsion of film stock to video embedded onto magnetic tapes. Moving images are projected through various equipment, developed as early as the 1890s, each projector suited to the type and size of the film stock which varied from 35mm and 16mm, to super 8 for personal use. Today’s moving images are captured using a wide variety of digital technologies, techniques, and software.

Moving images or continuous action photographs evolved from silent films to those wedded to sound tracks, synchronized through visible symbols on the film, by using scores, and through sound embedded onto film tracks.

Composition

Moving images are produced on photographic film consisting of three or four layers: a strip or sheet of transparent plastic film base which is called the base layer. The base layer is supposed to be dimensionally stable and was either nitrate film (discontinued in the US by 1951), cellulose acetate (safety film) used throughout the twentieth century, completely replacing nitrate film by 1951, and now polyester. The images are embedded into the emulsion layer containing microscopically small, light-sensitive silver halide crystals. The two layers glued together in the binder or gelatin layer. The sound track is another layer that is synchronized with the film and runs along the sprockets. Color film was first black and white film that was colored until the color dyes (red, green, yellow, and blue) were embedded in the various emulsion layers, seen commercially by 1935.

Magnetic media for moving images consists of a base layer of acetate or, today, polyester; an emulsion layer with magnetic filings; and a gelatin binder layer. The image, and sound, is encoded in the emulsion layer.

Playback equipment

The equipment for playback, first invented in the 1880s, is equally varied, evolving along with recorded sound, and now with computer technology. Play back moving images on the appropriate equipment to minimize damage to the sound (magnetic layer) and to the base. All equipment should be kept in working order, and cleaned before and after use. This is particularly important for playback equipment designed for magnetic media. Copy, reformat, and today digitize for frequent access by patrons.

Storage and handling

All moving images on reels should be stored wound tight, without the flanges, in appropriate storage containers. The containers can be stored flat. Moving images on magnetic tapes should be stored upright in their cassettes. All intellectual information about content and production should be either linked within the catalog or database, or affixed to the storage container.

A stable environment for long-term storage is a must. Long-term storage for black and white film stock can be at 40 degrees Fahrenheit and 35-50% relative humidity. Color film stock should be stored at or below freezing if possible. Nitrate films should be stored below freezing and should be isolated from all other film stocks.

It is essential that nitrate film be isolated from all other film stock, stored according to hazardous materials standards and in appropriate storage facilities. The main nitrate film vault in North America is located in Culpepper Virginia outside Washington, D.C. and is under the domain of the Library of Congress. Extremely flammable in its deteriorated state, today nitrate film is duplicated for use onto a safety film and then the original stored away. It’s nitrate film that was the cause of the many film studio fires in the twentieth century. Deteriorated nitrate film must be disposed of according to federal hazardous waste guidelines.

Moving images on magnetic tapes can be stored at room temperatures or slightly below (65-68 degrees Fahrenheit) at a relative humidity between 35 -50%.

Store all moving image film and magnetic media in the dark if possible. All should be stored in appropriate preservation quality storage containers. Avoid exposure to water and mold.

Summing it up

Moving images are found on film stock and magnetic media as well as in digital files. Use professional guidelines to determine if the materials fit within collection scope. Store in dry storage areas in appropriate storage containers, away from moisture, excessive heat, and light. Make copies for play back by researchers and staff. Store the originals for limited use and future copying. Keep playback equipment in useable condition, cleaning before and after use, especially when copying magnetic media.

Read more about film and its preservation issues:

<a href="https://lucidea.com/author/miriam_kahn/" target="_self">Miriam Kahn, MLS, PhD</a>

Miriam Kahn, MLS, PhD

Miriam B. Kahn, MLS, PhD provides education and consulting for libraries, archives, corporations, and individuals. See Miriam’s pieces for Lucidea covering library technology and skills for special librarians. Also check out SydneyEnterprise, and GeniePlus, Lucidea’s powerful integrated library systems.

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