A photographer’s contact sheet gives context to a single picture — it fills in its scene and characters, and provides the viewer with a better idea of what really happened. But it also highlights the seemingly infinite ways photos can be edited — tweaked slightly to convey different emotions. A new Magnum Photos Contact Sheet Exhibition, on display at Milk Gallery through July 13, explores the process behind the making and editing of many iconic images. There’s Elizabeth Taylor’s famous beach scene in 1959, Jackie at JFK’s funeral in 1963, Paul Fusco’s powerful pictures of Americans saluting the RFK Funeral train in 1968. The show, which puts marked-up contact sheets alongside their final selections, is a tribute to both American photography — and photo editing. Click through our slideshow (and click the images to zoom in on contact sheets) for highlights from the show.