"Born in 1941, he began making eight-millimeter films in the mid-’60s. The precipitating event, he told the writer Scott MacDonald in a 2002-3 interview, was a program of Stan Brakhage films that Mr. Gehr caught in New York on a rainy night. The works excited him partly because in their abstraction and attention to color, texture and rhythm they were closer to his experience of 20th-century painting than of movies, and he continued to seek out more of the same. He eventually ended up at the Millennium Film Workshop and borrowing a light meter from the filmmaker Ken Jacobs (with whom Mr. Gehr shares an interest in early cinema). As he walked around New York reading light, as it were, Mr. Gehr discovered “the character of light” and learned about “cinema’s dependency on light.”