Even by the standards of 19th century photographers, Linnaeus Tripe is obscure, so to have the National Gallery of Art and New York City’s Metropolitan Museum of Art mount a joint retrospective is rather unexpected. Tripe—born in 1822, almost two decades before the invention of his medium—photographed broad swaths of India and Burma on official business on behalf of the East India Company and the British government. Tripe’s work was almost entirely unknown to scholars of photographic history until 1977, and even after that he remained overlooked, at least until now. Using top-flight equipment during the 1850s, a period of rapidly changing photographic technology, Tripe made images of south Asia’s architectural details and natural landscapes in appealingly soft, sepia tones, but his photographs are rigorously composed, with an unfailing precision that reflects his training as a surveyor and a military officer. The canon of photographic history is filled with images of exotic, colonial scenery, but Tripe’s oeuvre is a welcome addition. Sept. 21–Jan. 4 at the National Gallery of Art. Free.