Recovery of Degraded-Beyond-Recognition 19th Century Daguerreotypes with Rapid High Dynamic Range Elemental X-ray Fluorescence Imaging of Mercury L Emission

作者：Kozachuk Madalena S; Sham Tsun Kong^*; Martin Ronald R; Nelson Andrew J; Coulthard Ian^*; McElhone John P

来源：Scientific Reports, 2018, 8(1): 9565.

DOI：10.1038/s41598-018-27714-5

A daguerreotype image, the first commercialized photographic process, is composed of silver-mercury, and often silver-mercury-gold amalgam particles on the surface of a silver-coated copper plate. Specular and diffuse reflectance of light from these image particles produces the range of gray tones that typify these 19th century images. By mapping the mercury distribution with rapid-scanning, synchrotron-based micro-X-ray fluorescence (mu-XRF) imaging, full portraits, which to the naked eye are obscured entirely by extensive corrosion, can be retrieved in a non-invasive, non-contact, and non-destructive manner. This work furthers the chemical understanding regarding the production of these images and suggests that mercury is retained in the image particles despite surface degradation. Most importantly, mu-XRF imaging provides curators with an image recovery method for degraded daguerreotypes, even if the artifact's condition is beyond traditional conservation treatments.

• 出版日期2018-6-22
• 单位Saskatoon; Canadian Light Source Inc; Canadian Light Source Inc.