Pre-production Snow's production notes for
Wavelength show variations on the concept of an extended zoom that moves from a
wide shot to a
close-up. The film emerged from an exercise playing with combinations of words, clustered around "room", "wave", "length", "Atlantic", "time", and "ocean". Snow's ideas for the final close-up included a photograph of a "beautiful blond white nude girl", a window, a picture of
Billie Holiday, a
Tom Wesselmann painting, a photograph of a child, or a calendar featuring an autumn landscape. Snow cast the film from his circle of friends. He selected Amy Taubin because of her previous acting experience in a
Broadway adaptation of
The Prime of Miss Jean Brodie. His notes for her scene included the idea to ask Taubin to masturbate. Filmmaker Hollis Frampton volunteered to appear in the film after Snow asked for "somebody to die for me". Snow spent a year preparing notes and looking for a space to film. To prepare the loft for filming, he placed the photograph of the East River on the far wall of the room.
Wavelength was shot in a loft on
Canal Street over the course of a week in December 1966. Snow borrowed a
Bolex 16 mm camera and
Angénieux zoom lens from filmmaker
Ken Jacobs. He mounted it on a high platform from which it could capture more of the street scenes outside. The distance from the camera to the opposite end of the room was around . Because the camera could only record 3 minutes of footage before needing to be reloaded, Snow divided the film's runtime into about 18 segments and marked the positions of the
zoom lens for the start and end of each segment. The scenes were shot out of order, with Frampton's death scene recorded first to accommodate his schedule. For the final scenes showing the wave photograph, Snow had to physically move the camera from its original position, having reached the limitations of the zoom lens. He shot on multiple types of film stock to produce changes in the light and
grain in the image. These included
Kodachrome,
Ektachrome, Kodak colour negative,
Agfachrome colour
reversal,
DuPont black-and-white reversal, and
Ansco stocks. Snow experimented with expired film, as well as film intended for outdoor lighting. Additional changes to the colouration were achieved by shooting during both day and night conditions, and by using
colour gels or
photographic filters.
Soundtrack For the film's soundtrack, Snow initially considered increasing the volume in an extended
crescendo. After deciding a
glissando would be more suitable, he developed plans to record it on a trombone or violin and mix together multiple takes to fill the duration of the film. Ted Wolff, who worked at
Bell Labs, was interested in the project and suggested using the pure tone of a sine wave produced by an audio oscillator. Wolff worked with Snow to build a motor that controlled the oscillator. Snow had intended to make use of whatever sync sound was recorded during filming but made an exception for the music on the radio. During the original shoot,
Joan Baez's cover of "
The Little Drummer Boy" was playing. Feeling it did not fit well in the film, Snow replaced it with "Strawberry Fields Forever", which had just been released when he was editing the film. Snow initially mixed the soundtrack such that the sync sound was on the film's
optical soundtrack and the electronic glissando was on a separate
reel-to-reel tape. This would give him the ability to adjust the tape playback based on the acoustics of each screening venue. ==Structure and analysis==