Porter was the brother of realist painter Fairfield Porter, who introduced his sibling early on to Alfred Steiglitz; Steiglitz showed Eliot's black-and-white landscapes at his famous gallery, An American Place, in 1938. But the photographer's training was in the biomedical sciences, and that background certainly influenced his work, especially the photographs of birds he made throughout his life. Ketchum took a more artistic path from the start, studying with Robert Heinecken at UCLA in the late 1960s and going on to produce color images in which the natural world was flattened even more than Porter dared. In that early work, the busy detail of nature dissolves into an abstraction that seems to cross-pollinate field painter Jules Olitski with action painter Jackson Pollock. "Porter was at heart a scientist, albeit one with a remarkably imaginative and poetic eye," says John Rohrbach, the Amon Carter museum's senior curator of photographs. "Ketchum, on the other hand, is at his core an artist. His photographs do not merely describe the world but are also tools for exploring how we see it."