Term used to describe mid-nineteenth-century American landscape painting emphasizing light and its effects. Less a style than a sensibility, luminism anticipated impressionism’s responsiveness to light but otherwise shared little with that style. Luminist paintings emphasize precisely drawn detail, virtually invisible brushwork, and lucidly measured space. Effects of light and atmosphere are achieved through elegantly nuanced gradation of tone, which often produces a hushed radiance. Reflections and carefully observed renderings of the effects of light on variously textured surfaces often contribute to a delicate and unrhetorical stillness. Typically lyrical and meditative in mood, luminist painting evokes spiritual mysteries embodied in nature. Hudson River School painters often worked in a luminist mode, particularly in the 1850s and 1860s when the approach was most popular. By about 1880 most artists had lost interest in luminism.
First given currency in a 1954 article by John Baur, the name meant nothing to the artists whose work is called luminist. The tendency originated spontaneously in the 1830s, never became an organized movement, and had no leader. In its international context, luminism can be seen as an American manifestation of tendencies associated with romanticism. Luminism’s possible sources include the landscapes of Claude Lorrain and Caspar David Friedrich, seventeenth-century Dutch seascapes, the Transcendentalism of such writers as Ralph Waldo Emerson and Henry David Thoreau, and, after about 1840, the vogue for crystalline daguerreotype images. Baur named Fitz Henry Lane and Martin Johnson Heade as central figures. Many of John Kensett’s paintings epitomize the adaptation of Hudson River School principles to luminist poetics. Others whose work is often included under the luminist rubric include Alfred Thompson Bricher, Frederick Church, Sanford Gifford, and Robert Salmon. The historical and critical literature has used the term inconsistently. Some writers restrict its application to a small core of views that summarize luminism’s central features, while others use it more loosely to refer to nearly any pre-impressionist painting that stresses analysis of light.
http://www.nga.gov/content/dam/ngaweb/research/publications/pdfs/american-light.pdf Entire text of seminal National Gallery of Art 1980 exhibition catalogue, American Light: The Luminist Movement, 1850–1875 by John Wilmerding, et al., including interpretive essays, bibliography, and images