Living Colour

Posted on Tuesday 25 May 2004 to Visions and Illusions

"No longer does the painter require a palette to command the sun,
instead the sun, rendered his assistant, will give colour and life to his work." -- Louis Ducos du Hauron

View of the city of Agen in Gascony in South-Western France. The cathedral which dominates this scene is St. Caprais which was built in the 12th century. In the foreground is the Canal des Deux Mers (Canal of the Two Seas) so named because it connects the Mediterranean to the Atlantic Ocean. Not far from where this picture was taken, the canal passes over the Garonne River, suspended high above its waters by a 580 metre long aqueduct.

This picture was taken taken by Louis Ducos du Hauron in or around 1877 and is one of the world's oldest colour photographs and the earliest one of an outdoor scene. Unlike the photography of Sergei Mikhailovich Prokudin-Gorskii which, based upon the pioneering work of James Clerk Maxwell, worked by projecting and combining the light of a red, green and blue images, Ducos du Hauron used a colour subtractive system essentially identical to the one used in colour photography today.

As with Maxwell's method, the photograph is made up of thee separate images each taken with a different coloured filter. The negative of each image was then used to create a positive of light-sensitised gelatin which was stained with its corresponding colour. It had long been known that gelatin treated with chromate salts if exposed to light became insoluble in water. After the soluble parts were washed away a transparent image remained stained as either cyan, magenta or yellow.


The final picture was produced by layering the stained gelatin plates over an white background.

Below is the cyan plate taken from an earlier image made in 1870 by Ducos du Hauron. A three colour carbon print known as "Diaphanie" (1870 Diaphanie, incidentally, refers to the art of simulating stained-glass with paper).



Only a few other examples made by Ducos du Hauron survive.
1876
1879

Ducos du Hauron did not prosper from his invention. He fought and won and then settled on amicable terms a priority dispute with fellow inventor and compatriot Charles Cros but Ducos du Hauron's process was cumbersome and the pictures were laborious to produce. Worse, colour photography was being held back by the poor colour sensitivity of the film in use in that era. Mid-nineteenth century film was really only sensitive to blue light and very little else.

Today, Ducos du Hauron is at least as well known for his other invention which also was based on the subtractive combination of colours: three dimensional anaglyphic images printed onto paper and viewable by using glasses with red and blue lenses.


Louis Ducos du Hauron in 3D