The extraordinary precision of daguerreotypes—one-of-a-kind images on silver-plated copper sheets—is demonstrated in a view of Paris made in 1849 by Choiselat and Ratel, in which even the buttons on the uniform of a distant soldier are visible through a microscope. Preservation of daguerreotypes in period and modern housings are shown, and the risks of chemical cleaning are pointed out on a Southworth and Hawes portrait that a well-intentioned owner tried to clean in 1934.
A two-part panorama of the first photographic printing firm, Reading Establishment (Talbot and Henneman, 1846), details the steps involved in the paper print process, which was invented by Talbot and which gradually supplanted daguerreotypes in the 1850s. In its early days, photography was handcrafted, and each photographer's work had a particular texture, tone, and color, the result of individual chemical recipes and procedures. Five splendid salted paper prints from the 1840s and 1850s by Louis Robert, David Octavius Hill and Robert Adamson, Gustave Le Gray, Frank Chauvassaigne, and Louis-Désiré Blanquart-Evrard featured in the exhibition demonstrate this process.
Two 1860s albumen silver prints by Carleton Watkins reveal how conditions of storage and display affect photographs. One print, richly printed and toned, never mounted, and apparently stored in ideal conditions, is clear, intense, and luminous; the other print, which was framed and long exhibited before joining the Metropolitan's collection, is discolored and stained from light and the poor materials of its mount and wood frame.
Highlighting the critical role of the conservator, a platinum print of a male nude by Thomas Eakins (ca. 1890) is displayed alongside a full-scale photograph of the print prior to treatment. An explanation of how the conservator restored the photograph to structural stability and aesthetic integrity describes aspects of deterioration and conservation. The state-of-the-art analytical tools of the conservator are explored through a turn-of-the-century photograph by Edward Steichen, an artist who experimented with a variety of painterly photographic techniques that rendered the works difficult to analyze. The precise elemental makeup of such pictures can now be discovered through non-destructive X-ray fluorescence, which enables the conservator to track an artist's technical development and to make more appropriate recommendations for treatment, storage, and exhibition.
Technical methods to help determine authenticity, a major concern of collectors, curators, and other connoisseurs, are also displayed. Analysis of microscopic fibers from photographic paper can help to date a work, as can the presence of optical brighteners that were added to many photographic papers after World War II and are visible under ultraviolet light. The issue of "vintage prints" (prints made close to the time of the original negative) is presented through two dramatically different black-and-white prints of Berenice Abbott's 1925 portrait of writer Djuna Barnes, one made in the 1920s, the other in the 1980s.
Artificially aged samples of five-color processes—four-color pigment, chromogenic (the most common), silver dye bleach, dye diffusion transfer (Polaroid), and ink jet—illustrate the degree to which each of these processes is susceptible to deterioration, underscoring the fact that museums must take special steps to preserve even the most contemporary photographs.