Filmstrip

The filmstrip was a common form of still image instructional multimedia, once commonly used by educators in primary and secondary schools (K-12), now overtaken by newer and increasingly lower-cost full-motion videocassettes and DVDs. From the 1940s to 1980s, filmstrips provided an easy and inexpensive alternative to 16mm projector educational films, requiring very little storage space and being very quick to rewind for the next use. Filmstrips were large and durable, and rarely needed splicing. They are still used in some areas.

Technology

A filmstrip is a spooled roll of 35 mm positive film with approximately thirty to fifty images arranged in sequential order. Like 16 mm film, a filmstrip was inserted vertically down in front of the projector aperture, rather than horizontally as in a slide projector. Therefore, the frame size is smaller than normal 35 mm film. Two image frames of a filmstrip take up the same amount of space as a single 35mm frame, including its guard band, so that a 25 exposure 35mm film can contain fifty filmstrip images. Early celluloid filmstrips had a habit of melting or combusting from the intense and sustained heat of the projection lamp.

Typically, a filmstrip's running time was between ten and twenty minutes. Depending on how they were narrated or produced, filmstrips (which often came with an Instructor's Guide) were flexible enough to be used in both self-paced learning formats or a full classroom. In addition to a standard classroom wall or screen projector, personal film display units were available with a screen size of approximately eight inches diagonal for up-close viewing by one or two people.

The instructor would turn on a film projector that would show the first frame (image) of the filmstrip. The instructor then turned on a 33 RPM record or cassette tape containing the audio material for the filmstrip which included narration. At the appropriate point, a tone would sound, signaling the instructor (or a student volunteer/assistant) to turn a knob, advancing to the next frame. Later, technical improvements allowed the projector to advance the film automatically.

Film production

By the latter part of the 1960s, such firms as Warren Schloat Productions, CBS, The New York Times, Scott Education, Coronet, Sunburst Media, and Guidance Associates were producing titles featuring photographs by famous artists and of notable events with a synchronized audio track. The music and narration for the filmstrip originally came on a vinyl album.

In the early 1970s, audio technology advanced, and vinyl albums gave way to audio cassettes. Filmstrips also moved beyond traditional arts and humanities courses, branching into the science, vocational, and technical subject areas.

Automatic film advance

During the 1970s, advanced projectors became available, and these projectors would automatically advance the film by means of a 50 Hz subaudible tone recorded on the cassette that would be detected by the projector, and automatically advance the frame. Most cassettes accompanying filmstrips in the 1970s and 1980s would have the same audio material on both sides of the tape. One side would have audible tones for the older projectors, and the other side would have the subaudible tones for the newer automatic projectors. Some select filmstrip releases had both audible and subaudible tones combined, making the filmstrip and its companion cassette compatible with any filmstrip projector. If improperly set up, the narration and film would not be synchronized.

Decline and obsolescence

The 1980s brought the advent of the video cassette recorder (VCR), and advancing technology meant increasingly affordable VCRs. When VCRs became within reach for most school districts' budgets, this marked beginning of a decline in filmstrip use. Video instruction combined the ease of the filmstrip with automatically synchronized audio and the dynamic images of television. By the early 1990s, the vast majority of filmstrips producers that were not equipped to compete with video either closed or sold their businesses.