When asked for his advice on how to take pictures, Robert Frank famously replied: "Keep your eyes open. Don’t shake. Don’t blink.” This spring season, Sotheby’s Photographs auction will offer important early images by Frank, including those made in Peru and Paris during the late 1940s, as well as iconic examples from The Americans, Frank’s renowned book of 83 images published in 1958. Click ahead for nine images by the legendary photographer.