MAGNUM CINEMA: Photographs From 50 Years of Movie-Making, with an introduction by Alain Bergala (Phaidon Press Limited: $60; 360 pp.) This sumptuous book is the result of an obvious idea finely executed. For half a century, Magnum, the world's most prestigious agency, has been sending its celebrated photographers to focus on that ever-glamorous subject, the movies and the resulting symbiosis has been remarkable. Here is Henri Cartier-Bresson, who once worked as Jean Renoir's assistant, capturing Marilyn Monroe (above), Eugene Smith shooting Charlie Chaplin and Buster Keaton on the set of "Limelight," Elliot Erwitt with Marlon Brando on "On the Waterfront." Some of the work, like Dennis Stock hanging out with James Dean and Magnum's exclusive rights to "The Misfits" set, has developed its own reputation, but the book's unfamiliar photographs, like Nicolas Tikhomiroff's coverage of Orson Welles' "Chimes at Midnight" or Eve Arnold's portrait of an intent Paul Newman at the Actors' Studio, are equally striking. Most movie photo books are ephemeral by nature; this is one to savor.