Wiktionary
n. 1 (context photography English) A school of artistic photography that emphasized using photography to mimic certain styles of contemporary painting, that flourished in the late 19th and early 20th centuries 2 Any artistic use of photography to imitate painting, especially using pictorial conventions
Wikipedia
Pictorialism is the name given to an international style and aesthetic movement that dominated photography during the later 19th and early 20th centuries. There is no standard definition of the term, but in general it refers to a style in which the photographer has somehow manipulated what would otherwise be a straightforward photograph as a means of "creating" an image rather than simply recording it. Typically, a pictorial photograph appears to lack a sharp focus (some more so than others), is printed in one or more colors other than black-and-white (ranging from warm brown to deep blue) and may have visible brush strokes or other manipulation of the surface. For the pictorialist, a photograph, like a painting, drawing or engraving, was a way of projecting an emotional intent into the viewer's realm of imagination.
Pictorialism as a movement thrived from about 1885 to 1915, although it was still being promoted by some as late as the 1940s. It began in response to claims that a photograph was nothing more than a simple record of reality, and transformed into an international movement to advance the status of all photography as a true art form. For more than three decades painters, photographers and art critics debated opposing artistic philosophies, ultimately culminating in the acquisition of photographs by several major art museums.
Pictorialism gradually declined in popularity after 1920, although it did not fade out of popularity until the end of World War II. During this period the new style of photographic Modernism came into vogue, and the public's interest shifted to more sharply focused images. Several important 20th-century photographers began their careers in a pictorialist style but transitioned into sharply focused photography by the 1930s.