MR. POLAROID tells the little-known story of the man behind the camera, a Harvard dropout named Edwin Land. Over a half century ago, before the smartphone, Land was dreaming up “a camera that you would use as often as your pencil or your eyeglasses.” He would also come to believe his company was “on its way to lead the world — perhaps even to save it.” Hubris, technology, brilliance, and a billion photographs a year are all part of the rollicking Polaroid story.