Niépce's photograph

The story

Catching the light

Since ancient times people had known about a curious effect: if there is a small hole in the wall of a dark room, an upside-down picture of whatever is outside, with its colours and movements, appears on the opposite wall. This is the idea behind the “camera obscura”, which means “dark room” in Latin. Arab scientists such as Ibn al-Haytham studied it carefully in the 11th century, and Renaissance painters such as Leonardo used it to understand perspective. Once a lens was added, the camera obscura became a portable device: a box in which you could see a landscape and trace it with a pencil.

But nobody knew how to fix that picture: the light came in and the image appeared on the wall, but it vanished as soon as the box was moved. What was needed was a substance that would change when light fell on it and keep the mark.

An inventor in the countryside

Joseph Nicéphore Niépce was born in 1765 in Chalon-sur-Saône, in France, into a wealthy family of lawyers. During the Revolution he was a soldier, then he went back to his lands and devoted himself to experiments: with his brother Claude he even invented an engine, the “pyréolophore”, which they used to drive a boat on the river. He was a passionate inventor, but he was also always short of money.

Around 1816 Niépce became interested in a new invention, lithography, a printing technique done by drawing on stone. He was not good at drawing, and his son, who used to do it for him, had left to join the army. So he began to look for a way to make light draw the pictures. He tried silver salts, which darkened in the light, but he could not fix them. Then he found a different substance: bitumen of Judea, a kind of natural asphalt which, when exposed to light, becomes hard and no longer dissolves in solvents.

“View from the Window at Le Gras”

Niépce coated a pewter plate with a thin layer of bitumen and placed it inside a camera obscura, in front of the window of his country house at Saint-Loup-de-Varennes, in Burgundy. He left it exposed for many hours, perhaps even days, while the sun moved across the sky. Then he washed the plate with lavender oil and white petroleum: the bitumen that had not received light dissolved, leaving only the part hardened by light. A picture appeared on the plate: rooftops, a courtyard, a piece of sky, blurred but recognisable. It was sometime between 1826 and 1827: the oldest photograph known had been born.

Niépce called his process “heliography”, meaning “writing with the sun”. The image, however, was faint, needed a very long exposure and was not easy to repeat. In 1829 he teamed up with another man who was studying the same thing, Louis Daguerre, a painter and inventor of light shows, in Paris. Niépce died in 1833, without seeing the success to come.

After Niépce

In 1839 Daguerre carried on and invented the “daguerreotype”: a silver plate polished like a mirror, made sensitive with iodine vapour and developed with mercury vapour, which gave a very sharp picture after only a few minutes of exposure. The French government bought the invention and gave it to the world on 19 August 1839: within a few months, photographers' studios were springing up everywhere. Meanwhile, in England, William Henry Fox Talbot invented a system using a paper negative, from which many copies could be printed: this is the principle of film photography.

In 1888 the American George Eastman launched the Kodak camera, small, with the film already inside, which anyone could use: its slogan was “You press the button, we do the rest”. Then came colour, instant photography, 35-millimetre film and, in 1975, the first digital camera, built by a Kodak engineer, Steven Sasson: it weighed about four kilos, recorded black-and-white pictures of very few pixels and took twenty-three seconds to save one.