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.