The Ronald G. Becker Collection of Charles Eisenmann Photographs Using the Collection The collection of 1412 images can be accessed via the Library's CONTENTdm server and is fully searchable by keyword, subject, and image number. The item level inventory of the collection (in Excel) can help with formulating searches and sorting. About the Photographs The most common method of photography during the 1870s and 1880s was the wet plate albumen process. Albumen prints are characterized by a warm sepia tone that distinguish them from later silver gelatin prints. Eisenmann's images are noted for particularly being sharp, clear, and well-posed. The most common formats were cartes de visite and and cabinet cards.