PHOTOGRAPHS CAN capture exceptional moments in an iconic way, making the original experience “present” emotionally as well as pictorially. The photo of U.S. Marines raising the American flag on Iwo Jima’s Mt. Suribachi “means a Marine Corps for the next 500 years,” Secretary of the Navy James Forrestal said in 1945. The image of John F. Kennedy Jr.’s boyish salute as his father’s casket left Washington’s St. Matthew’s Cathedral in 1963 helped cement the “Camelot” myth into its seemingly impregnable place in American public life. The “Earthscape” pictures shot by Apollo 8 astronauts at Christmas, 1968, continue to play a not-insignificant role in today’s environmental movement.