LA PHOTOGRAPHIE DES OBJETS COLORÉS AVEC LEURS VALEURS RÉELLES: MANUEL DES PROCÉDÉS ISOCHROMATIQUES ET ORTHOCHROMATIQUES.

Paris: Gauthier-Villars, 1887. First edition. 8vo., ix, 193 pp., two mounted plates of which one is a chromolithograph, and the other has two monochrome photoglypties; with two additional monochrome carbon photographs with a printed tissue guard; 15 engraved figures in text. The first tissue guard has five small holes where it once adhered to the surface of the chromolithographic plate. This copy is bound in publisher's red cloth titled in black ink on the upper cover and spine. A fine, unopened and nearly new copy, containing two additional plates not usually found in the wrapper copies. Additionally, this copy is Signed and Inscribed by the author. "Dr. H. W. Vogel discovered in 1873 that dyes added to photographic materials extended their sensitivity to colours other than blue. In 1882 commercial dry plates were produced, and these isochromatic, or orthochromatic, plates soon came into general use. Because they were much more sensitive to blue than green, they were normally exposed through a yellow filter to balance up the exposure. In 1884 Dr. Vogel discovered a method of sensitizing plates to orange as well as green light." Coe, Brian, Color Photography: The First Hundred Years, 1840 - 1940, p. 34. These discoveries were fundamental for correct color photography. Of Vogel's invention of color sensitizers, Eder states on p. 647, "by the addition of dyes to silver bromide collodion he obtained practical three-color separation negatives, the results of which he exhibited at the Paris Exposition of 1878."

This French edition, a unique title, is based upon earlier texts by Vogel. Translated into French by Henry Gauthier-Villars, and augmented with notes from the author. Roosens and Salu 7664.