449
region of the spectrum, du Hauron started to sensitize
his plates using dyestuffs. To obtain some red sensitivity,
du Hauron started to use chlorophyll.
Ducos du Huron’s earliest surviving color photo-
graph, a view of Angoulême, dates from 1877. For
example, this photo is reproduced on page 29 in Histoire
mondiale de la photographie en colours, a book by
Roger Bellone and Luc Fellot, published in 1981.
Preceding Ives, Ducos du Hauron developed one-
shot prototype color camera, Photochromoscope, for
recording color photographs.
Already in 1868 du Hauron had described in a let-
ter another potential color photography method which
was the screen plate technique. However, the letter was
not published until 1897. In this process an emulsion is
exposed through a screen consisting of a set of very fi ne
lines of red, yellow and blue drawn on glass. Through
the red lines only red light could pass and expose the
emulsion behind the screen. Likewise, the blue and yel-
low transmitted only blue and yellow light, respectively.
The photographic plate exposed behind the screen was
developed and a positive copy made. The positive copy
was then overlaid with a similar screen in exact register.
The fi ne, primary-color lines would be blended in the
eye so that one could see a the original colors of the
object. This technique was fi rst realized by Joly using
the correct primary colors and later perfected by the
Lumiére brothers when they introduced the Autochrome
process in 1907.
In 1897 du Hauron conceived the idea of using a
tripack for recording color photographs. Instead of us-
ing beam-splitting devices in the camera, he introduced
a dialytic selection of the light rays by an alteration
of fi lters and light-sensitive sheets of fi lm or plates.
It consisted of a glass coated with a transparent layer
of (non-orthocromatic) blue-sensitive silver bromide,
next to a yellow fi lter, to let red and green light to
pass to a green-sensitive emulsion, a red fi lter and
then a red-sensitive emulsion. A suggestion of Ducos
du Hauron is to manufacture a complete, or quintuple
(three sensitive surfaces and two screens), set of ele-
ments for use in an ordinary dark slide. This set he calls
polyfolium chromodialytique. After being developed,
a yellow print was made from the blue negative, a
magenta print from the green negative and cyan print
from the red negative. By combining the prints of
those complementary colors, full-color reproductions
could be made of the recorded tripack plates. However,
since no suitable color-sensitive emulsions existed at
that time, du Hauron was not able to show the full
potential of his invention. It was not really until the
1930s du Hauron’s could be demonstrated, when the
Kodachrome fi lm was introduced.
In 1899 du Hauron introduced a dual purpose instru-
ment, which was build by Lesueur, the so-called Méla-
nochromoscope which was a combined recording and
viewing instrument for three-color photographs.
Hans I. BjelkhagenBiography
Ducos du Hauron was born on December 8, 1837 in
Langon, Gironde, France. In 1864 du Hauron invented
and patented one type of a cinematograph. On February
23, 1869, du Hauron was granted his fi rst French patent
(Patent No. 83061, dated November 23, 1868) on additive
and subtractive color processes applied to photography,
as well as the screen color technique. His fi rst book:
Les couleurs en photographie, solution du problème,
published in 1869, was an important contribution to the
understanding of additive and subtractive photographic
color processes. His work was exhibited regularly at the
Paris Photographic Society from 1869 on. In 1874 du
Hauron was granted a French patent on the single-shot
photochromoscope (Patent No. 105881, dated December
15, 1874). In 1876 he was granted a British patent on Col-
or Photography (Patent No. 2973, dated July 22, 1876).
His patents cover most of modern color photography
techniques. Later, in 1892, du Hauron patented also the
anaglyph three-dimensional photographic method. His
outstanding achievements in photography was acknowl-
edged by being awarded the 1900 Progress Medal of the
Royal Photographic Society for his early work in three-
color photography. In 1912, he was made a Chevalier of
the Legion d’Honneur. He died 1920 in Agen.
See also: Color Theory and Practice: 1860–1910.Further Reading
L. Ducos du Hauron: Les couleurs en photographie, solution du
problème (A. Marion, Paris 1869)
L. Ducos du Hauron: L’héliochromie, méthode perfectionnée pour
la formation et la superposition des trois monochromes con-
stitutifs des hélichromes à la gelatine (Société d’Agriculture,
Sciences et Arts d’Agen, 1875)
L. Ducos du Hauron: L’héliochromie: nouvelles recherches sur
les négatifs hélichromiques; la rapidité trouvée, le paysage
et le portrait d’après nature (Société d’Agriculture, Sciences
et Arts d’Agen, 6 septembre 1875)
A. and L. Ducos du Hauron, Traité pratique de la Photographie
des couleurs, Gauthier-Villars, Paris, 1878.
A. Ducos du Hauron, La photographique des couleurs et le décou-
vertes de L. Ducos du Hauron, Gauthier-Villars, Paris, 1899.
E.J. Wall, History of Three-Color Photography, Focal Press,
Boston, 1970.
Roger Bellone and Luc Fellot, Histoire mondiale de la photog-
raphie en colours. Hachette Réalités. 1981, 55–88.DÜHRKOOP, RUDOLF (1848–1918) AND
MINYA DIEZ (1873–1929)
German photographers
Born in Hamburg, Germany in 1848 to working class