Scientists at the Canadian Light Source are using the synchrotron to restore photographs developed in the mid 1800’s using the first photo processing technique.
“It’s not that different from what is done with photographic film, you’re just doing it on silver,” said Dr. Ian Coulthard, senior scientist at CLS.
“It’s more of a physical process.”
First available in 1839, daguerreotype photography went out of style by 1860 - but in that short timeframe millions of daguerreotypes were created, Coulthard said.
To create a daguerreotype, a photographer first took a piece of silver or copper and polished it until the surface was reflective. Coulthard said the piece of metal was then exposed to chlorine or bromine gases to make the metal reactive.
After taking a picture the light creates an alloy, forming image particles - little bumps that reflect light to a viewer’s eyes, creating a picture.
Because the image was on metal, tarnish and oxidization quickly mask it, making it barely visible to the naked eye. It was also too fragile to polish.
“It’s an extremely delicate image because you’re talking about that image being only one micron of thickness. Imagine the finest hair on your head and imagine something 10 times thinner than that,” Coulthard said.
That’s where the CLS’s synchrotron comes in.
Coulthard received several daguerreotypes from the National Gallery of Canada’s Photography Institute in Ottawa.
He’s penetrating through 170 years of damage with a x-ray beam measuring 25 microns - about 40 times smaller than a grain of salt - collecting the image particles as the light tracks left to right on the daguerreotype.
The process takes about six hours for a daguerreotype that can sit in the palm of your hand, and the beam travels at about four milliseconds per spot so it doesn’t damage the thin layer that makes up the photo.
The daguerreotypes largely came from donors in North America and Coulthard hopes the synchrotron and the daguerreotype-application will be used to restore historic landscape photography.
