Polaroid’s 20×24 cameras, built in the late 1970s and named for the dimensions of their snapshots — 20 by 24 inches, are the largest living Polaroid cameras in the world. (There was once an even bigger one with 40×80 snapshots but the film has run out.) Five of these 20×24 cameras still exist, and one resides in New York City’s 20×24 Studio. The Studio’s director, artist John Reuter, demonstrates the 235-pound camera, and Christopher Bonanos, author of Instant: The Story of Polaroid, explains how this camera fits into Polaroid’s history.