Video, an Audiovisual Medium

4 The Use of Processors for Video Processing

In the early 1970s, video processors were constructed by engineers in a close exchange with video artists. They serve to control the electric voltage and bring about signal variations that cause the deflection of the individual scan lines. In contrast to the synthesizer, which in principle proceeds compositionally, generates image and sound, and links different objects, a processor analyzes the smallest units in the video, its wave forms, and in this way controls the image.

The Rutt/Etra Scan Processor,[4] developed in 1973 by Steve Rutt, Bill Etra, and Louise Rutt and with which, for example, Nam June Paik, Gary Hill, and Steina and Woody Vasulka worked, is particularly suited for video analysis — that is, for the control and modulation of electric signals. In the Scan Processor, the brighter parts of the image are strongly or slightly lifted up in their temporal progression according to the voltage, causing the horizontal lines to deflect vertically and sculptural forms to be generated. Abstract figurations are produced from videographic scan lines through the addition of power. In this way, in Vocabulary (1973), Woody Vasulka had separate image areas flow together to produce new forms based on equal brightness and color values. Gary Hill employed other functions of the device in Picture Story (1979), in which he reduced and enlarged keyed-in-that is, cut-out and inserted — image parts, and transposed the top-to-bottom and right-to-left relationships in the overall image.

Exemplary use of the functions of the Rutt/Etra Scan Processor is made in Steina and Woody Vasulkas’ video Noisefields (1974). In this work, additional electronic information (electronic snow) is keyed into a circular form that has been recorded by camera and processed in such a way that the impulse movement of the signal can simultaneously be seen and heard. In the process, the image content is determined by the modulation of unformed electronic oscillation processes — in other words, video noise. Thus, noise as a formless electronic basis that contains all of the frequencies to the same degree has the potential of auditive and visual configuration.

This effect of the feedback of the video image to the electronic raw material in sound is intensified in that a video sequencer, which regulates the deflection frequency of alternating image fields, transfers the audiovisual information that has been heightened into noise into a positive-negative switching with variable speeds. A noisy image-sound impression is produced, an electronic flicker effect. Noisefields thus represents the beginning of electronic signal processes.