Techniques developed by researchers from Western University for creating images of old, badly tarnished photographs could also be used to study other historic artifacts and fossils and prevent corrosion on modern materials.
Professor T.K. Sham and colleagues recently confirmed that a new synchrotron imaging technique they developed is just as effective for retrieving corroded daguerreotypes (the earliest form of photographs) as a technique they first reported on back in 2018, and can also be used no matter how badly damaged the image surface is from natural corrosion or cleaning attempts. The new research, which used beamlines at the Canadian Light Source (CLS) at the University of Saskatchewan (USask), is published in the Journal of Cultural Heritage.
“This technique can be used widely in all walks of science, from looking at tissues to materials science,” said Sham. “For example, you could determine whether or how a metal may be corrosion-resistant, or in the case of an already corroded material you can learn what the product of that corrosion is and its distribution on the surface, and then you can work back and think about how to prevent that corrosion from happening.”
Sham said many applications are possible because synchrotron X-ray is very tunable, which means it can pick out any element and find out what its chemical surrounding is and where it is placed in the sample, even imaging it layer by layer.
When it comes to the conservation of antiques, Sham’s research could be a game changer too, especially for studying artifacts or fossils that have severe surface deterioration.
As part of his new research, he uncovered images of a lady and a gentleman fashionably dressed in mid 1850s garments, and one of a baby peacefully wrapped in covers. All of these daguerreotypes, belonging to private collectors and the National Gallery of Canada, were badly damaged — slow deterioration mixed with cleaning attempts may have caused the tarnish.
He proved that this synchrotron technique is always effective as long as the image particles underneath the tarnish remain intact, a discovery advancing his 2018 study in Scientific Reports. This research was done using the VESPERS and the SXRMB beamlines at the CLS and at the Advanced Photon Source at Argonne National Laboratory near Chicago.
Read more on CLS website