An excellent survey of work by Chris Welsby, a British native now living in Canada who has spent three decades making films and gallery installations that borrow their forms from natural phenomena. For Tree (1974, 4 min.) he attached his camera to a tree branch on a windy day to create an amazingly complex relationship between the camera's movement and the movement of the grass and leaves. For his longest film, Estuary (1980, 55 min.), he fixed his camera to an anchored boat and over the course of three weeks exposed four seconds of film every 15 minutes: the compositions are determined entirely by the wind, the waves, and the tide, and close observation of the water, the landforms, and the shifts in light reveal the delicacy of nature's changes. Welsby's stance is essentially an ethical one, questioning how much control we should permit ourselves over our art—or our world. On the same program, which totals 127 minutes: Forest Bay Two (1973), Seven Days (1974), Sky Light (1988), and Drift (1994).