HELIOGRAPHY

Nicéphore Niépce, an amateur inventor living near Chalon-sur-Saône, a city 189 miles (304 km) southeast of Paris, was interested in lithography, a process in which drawings are copied or drawn by hand onto lithographic stone and then printed in ink. Not artistically trained, Niépce devised a method by which light could draw the pictures he needed. He oiled an engraving to make it transparent and then placed it on a plate coated with a light-sensitive solution of bitumen of Judea (a type of asphalt) and lavender oil and exposed the setup to sunlight. After a few hours, the solution under the light areas of the engraving hardened, while that under the dark areas remained soft and could be washed away, leaving a permanent, accurate copy of the engraving. Calling the process heliography (“sun drawing”), Niépce succeeded from 1822 onward in copying oiled engravings onto lithographic stone, glass, and zinc and from 1826 onto pewter plates.

In 1826/27, using a camera obscura fitted with a pewter plate, Niépce produced the first successful photograph from nature, a view of the courtyard of his country estate, Gras, from an upper window of the house. The exposure time was about eight hours, during which the sun moved from east to west so that it appears to shine on both sides of the building.

Niépce produced his most successful copy of an engraving, a portrait of Cardinal d’Amboise, in 1826. It was exposed in about three hours, and in February 1827 he had the pewter plate etched to form a printing plate and had two prints pulled. Paper prints were the final aim of Niépce’s heliographic process, yet all his other attempts, whether made by using a camera or by means of engravings, were underexposed and too weak to be etched. Nevertheless, Niépce’s discoveries showed the path that others were to follow with more success.