Portret van Robert T. Jeffrey before 1875

This photograph of Robert T. Jeffrey was made by Thomas Annan, sometime in the second half of the 19th century. This was the Victorian era, when photography was still a relatively new, and laborious, process. Annan likely used the wet collodion process, invented in 1851. This involved coating a glass plate with a light-sensitive emulsion right before exposure in the camera, requiring portable darkrooms for on-site development. The resulting glass negative would then be used to make prints. The ambrotype, as this print is, involves backing the glass negative with a dark material, often black paper or paint, which renders the image a positive. The final product is a unique, direct positive image on glass, with a somewhat milky appearance. These photographs were extremely popular at the time, before they gave way to more easily reproducible processes. The material and process are inextricably linked here: without an understanding of one, we could not understand the other.