Two classic films explore the properties and effects of the zoom. Described by critic Jonathan Rosenbaum as “the most consequential zoom shot in the history of cinema,” Michael Snow's Wavelength is structured on the principle of a zoom across a room accompanied by a sine wave as it progresses from its lowest note to its highest. It mixes narrative and formal elements with ease and drama, all the while posing rich questions about reality and cinema. Presented in a new preservation print, blown up to 35mm, Ernie Gehr's Serene Velocity “created a stunning, percussive head-on motion by systematically shifting the focal length of a stationary zoom lens as it stared down the center of an empty institutional hallway-thus playing off the contradiction generated by the frame's heightened flatness and the composition's severely overdetermined perspective. Without ever moving the camera, Gehr turned the fluorescent geometry of this literal Shock Corridor into a sort of piston-powered mandala. If Giotto had made action films it would be this” (J. Hoberman).