Robert Demachy (1859–1936) was the leading French Pictorial photographer of the late 19th and early 20th century. Pictorialism 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.
Demachy is best known for his intensely manipulated prints that display a distinct painterly quality. Demachy was particularly interested in nonstandard photographic processes and is noted especially for his revival of the gum bichromate process (invented in 1855 but little used until the 1890s), which allowed the introduction of color and brushwork into the photographic image (source).
He gave up taking photographs in early 1914, and never again touched a camera, even refusing to take snapshots of his grandchildren. No one was ever able to extract any reason from him for this sudden change, and it remains a mystery to this day.
Dans les coulisses by Robert Demachy (ca. 1897)
Behind the Scenes of the Opera by Robert Demachy
Behind the Scenes by Robert Demachy (1906)