In the late ’50s and early ’60s, attorney Marvin Lazarus (1918–1982) would periodically sneak out of his Manhattan office, cameras hidden under his clothes, to photograph some of the 20th century’s best-known artists (among them, Franz Kline, Marcel Duchamp, Louise Nevelson, and Alberto Giacometti). From 1959 to 1962, when he decided to leave the legal profession to try his hand at a fulltime career in photography, Lazarus also kept detailed notes recounting each of these sittings. We feature extensive excerpts of the never-before-published journals here, along with 14 of Lazarus’s remarkable portraits. His words and images offer sharp insights into the personalities, and the social landscape, of the postwar New York City art world.