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Hello, in Paris in 1839, the DIGRO type was announced to the world.

Louis de Gaulle had found a way to capture images that went through a lens onto a screen

in a sealed box, and to preserve those images for others to see in another place and at another

time.

This was the dawn of photography.

The Gers was a great feat of chemistry, technology and showmanship, and drew on years of experiment

with camera obscura going back to divinity and medieval China, and on the work of scientists

who knew some chemicals were active to light, but didn't know how to preserve those changes.

It was said DIGRO type said, quote, realize the dream that had been dreamt for a long time,

a way of making nature make images of itself.

There were more of a nightmare for Henry Fox Tolbert in England who had been working

on a very different way of capturing images and rushed to make his discoveries known

too.

With me to discuss the invention of photography are Simon Schaffer, Professor of the History

of Science at the University of Cambridge.

In Elizabeth Edwards, a Maritius Professor of Photographic History at De Montford University,

and Alison Morrison Low, Research Associate at the National Museum's Scotland.

Simon Schaffer much was known before the Gers about light and lenses.

So let's start with the idea of a camera.

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