Concurrent with the Impressionists and influenced by Emile Zola"s writings, the Naturalists believed that they were revolutionizing French painting by their focus on themes taken from the streets of Paris or from life in the provinces. In 1866, Zola began to advocate the examination of reality through an objective, scientific study of man. To achieve this in painting, the Naturalists sometimes relied on the infant medium of photography, which could lock in a spontaneity and documentary precision that painting and sketching could not always achieve. The Naturalists exerted widespread influence, with enclaves appearing in England and Scotland, Belgium, Holland, Hungary, Germany, Scandinavia, and the U.S. Using largely primary field research, Gabriel P. Weisburg has written the first comprehensive study of the sweeping implications of these documentary attitudes that grafted scientific advances onto the academic tradition.