The camera films a park landscape through the flat mirror blades of a small windmill. The film was shot in one continuous 400 foot take. The camera looks through the blades of the windmill, recording either what is behind or in front of the windmill blades. A rhythm determined by the speed and direction of the wind.

This film is one of a series of films (Wind Vane, Anemometer, Tree, Park, Estuary etc.) which uses an element present within the frame as a feedback device to control an aspect of the recording process. In this case it is the wind moving the leaves on the trees within the frame which also causes the windmill to rotate like a secondary shutter in front of the camera. This rotation of the mirrored windmill blades causes the image on the screen to alternate between the space in front of the camera, seen intermittently through the blades, and the space behind the camera, reflected in the blades. When the windmill reaches a particular speed, a third space is also created as the deep space of the picture plane fragments and becomes a two dimensional abstract surface of colour and light.

The duration of this film was limited by the length of a roll of unexposed film stock. The shape of the film, however, was entirely dependent on the strength and direction of the wind.

"In Windmill III, a mirrored windmill set before the camera divides the image into three distinct areas: the space in front of the windmill, the space occupied by the windmill itself, and the space behind the camera that is reflected in the blades. When the windmill turns slowly, the blades smoothly displace—or "wipe"—the front landscape with the reflected images. As the wind picks up, the windmill rotates faster and the reflected images blur, creating painterly smears across the foreground. By sectioning linear perspective, Windmill III not only challenges the standard presentation of space, it also highlights what is normally unseen - the space behind the camera."
(Village Voice April 25th 1989, NYC)