Serene Velocity is a 1970 American experimental short film directed by Ernie Gehr. Gehr filmed it in the basement hallway of a Binghamton University academic building, using a static camera position and changing only the focal length of the camera. It is recognized as a key work of structural filmmaking and has been inducted into the U.S. National Film Registry. Description Serene Velocity lasts twenty-three minutes and is silent. To make the film, Gehr locked his camera down in the center of a hallway, shooting several individual frames at a time. After each set of exposures, he changed the focal length on the lens, zooming in and then out in increasing increments. What begins as a small difference in apparent distance several frames at a time expands to extreme closeups and wide shots jumping back and forth. By the end of the film, the zoom into the end of the hallway reveals a set of double doors with daylight filtering through. Production In early 1970 Gehr was at SUNY Binghamton while Larry Gottheim was beginning to form a film department. Gottheim was impressed with Gehr's earlier short films Morning and Wait, and the two became acquainted when Gottheim replaced a damaged print of one of Gehr's works. With the encouragement of Gottheim and Ken Jacobs, Gehr taught two courses there during the summer session. He had been interested in making a film that explored "the intervals between frames–activating the screen plane from frame to frame more dynamically". One day during the session, Gehr was on his way to the film department's editing rooms in a basement and thought of the hallway as an ideal place to film. A long, plain area appealed to him as a good space to "maximize the tension between representation and abstraction". Gehr began shooting test footage in the basement hallway. He tested mid-range and extreme focal lengths in "bars" of 1, 2, 4, 6, and 8 frames. He decided to use bars of 4 frames, projected at 16 frames per second. This would have been roughly equivalent to 6 frames at 24 frames per second, but Gehr chose a lower frame rate so that each frame would remain on screen longer, accentuating the optical effects. He was surprised by the physical effect of watching the footage and felt nauseated afterward. The footage for Serene Velocity was shot over the course of one night. Gehr began