“Double Exposure,” by Robert Sullivan (Farrar, Straus & Giroux) “Double Exposure,” by Robert Sullivan (Farrar, Straus & Giroux) Timothy O’Sullivan came west after the Civil War to take pictures of the landscape and the indigenous people for the Clarence King and George Wheeler geological surveys. The photographs he left behind are both documentation and art. Ansel Adams, who discovered O’Sullivan’s work in the late 1930s, called the photographs “surrealistic and disturbing” (although he complained that they were “technically deficient”). Although O’Sullivan’s photographs are well known, the photographer’s life is largely undocumented.