Term coined c. 1950 by the art historian John I. H. Baur to define a style in 19th-century American painting characterized by the realistic rendering of light and atmosphere (see fig.). It was never a unified movement but rather an attempt by several painters working in the USA to understand the mysteries of nature through a precise, detailed rendering of the landscape. Luminism flourished c. 1850–75 but examples are found both earlier and later. Its principal practitioners were Fitz Henry Lane, Martin Johnson Heade, Alfred Thomson Bricher, David Johnson, and Francis Augustus Silva (1835–86). Several artists of the Hudson River School, among them Sanford Robinson Gifford, John Frederick Kensett, and Albert Bierstadt, painted works that could be considered examples of Luminism, as did such Canadian painters as Lucius R. O'Brien (e.g. Sunrise on the Saguenay, 1880; Ottawa, N.G.). The Luminists concentrated on nuances of light and atmosphere, an approach that may have been suggested by the new, dispassionate medium of photography.