Since the birth of cinema, more than a century ago, film stock was the medium on which people made, and viewed, movies. But film projection as we know it is taking its last breaths. As of last month, more than ninety per cent of theatre screens in the United States are digital. The projectors that take 35-mm. film have been replaced by digital setups that use hard drives instead of film reels and play with the click of a mouse instead of with the flip of a switch. In place of film reels, digital cinema packages (called D.C.P.s) are the new industry standard. The conversion has been more than a decade in the making, and Hollywood is saving big: “About a billion dollars a year—that’s a pretty good deal for the studios,” Patrick Corcoran, of the National Association of Theatre Owners (NATO), told me.