Understanding Early Photography
This website introduces a project at the Smithsonian’s Museum Conservation Institute (MCI). Our goal is to characterize surface properties and composition
using non-destructive scientific techniques, such as computational imaging, electron microscopy, and x-ray fluorescence. This site is designed to communicate
scientific and technical data to scholars and the general public.
Daguerreotypes are the earliest successful form of photography, dating from the mid 19th century. A light sensitive mercury-silver amalgam is formed on
a silver-plated copper sheet. Once exposed to light, the photograph must be developed immediately. The image layer remains light sensitive: it will fade
completely in extreme cases. Daguerreotypes are also very thin and easily damaged, so for these reasons they were placed in hinged custom cases, often called Union Cases.
Technical results from this study will provide greater understanding of the early photographic materials, as well as the nature of their degradation processes and products.