Photograph conservators provide preservation, conservation, and research into the history, aesthetics, and technology of images dating from the early history of the medium until the present day. They not only treat damaged and deteriorated works but also examine, document, and analyze them, recommend proper storage and housing, and monitor environmental conditions, such as light, temperature, relative humidity, and air quality, that affect the health of the collection.
The most common treatments for photographs are physical—mending a tear, relaxing a crease, or surface cleaning. Chemical treatments to revive faded or stained images are generally avoided, since they are experimental, unpredictable, and irreversible. Written, photographic, and analytical documentation are always an essential part of the treatment process, and professional conservators follow the Code of Ethics and Guidelines for Practice established by the American Institute for Conservation.
The Sherman Fairchild Center includes a darkroom equipped to re-create the full range of historic processes, enabling conservators and students to gain a detailed technical understanding of older works in the collection. Experimental samples produced here are also used in analytical studies and in accelerated aging tests to investigate the makeup and long-term stability of specific processes.
Areas of research have included the image color of Gustave Le Gray's salted paper prints; light sensitivity of daguerreotype plates; anoxic light studies on autochrome dyes; and marking inks for use on photographs.
The 2001 exhibition Photography: Processes, Preservation, and Conservation explained various photographic processes and explored issues of connoisseurship, condition, preservation, and treatment. It also included the following resources:
Glossary of Principal Photographic Processes, Arranged Chronologically
Basic Guidelines for the Preservation of Photographs