Warrah is a visual expedition along the lush coastal expanse of the Hawkesbury River Region. The complexity of the bush ecology is rendered through a playful use of the 3-color separation system of filming: the dappled Angophora trunks, the foliage, the patterns of shadows, water and cloud. The soundtrack is a recording of kookaburras calling to one another up and down the valley, echoing the layers of film images. After seeing early experiments in color photography at the Eastman House in Rochester, the Cantrills became interested in the question of color in film. Armed with a Bolex camera, they began a series of investigations into color separation techniques, arriving at what they called "time-color separations," a factor in which movement is expressed in different color values. Warrah advances this work with color filters that select and enhance saturation levels. Thus, a leaf floating downstream is seen as a fully saturated red, an eddy in the stream becomes a turbulent rainbow. More than a portrait of a place, this film is a treatise on form moving through time.