A History of Glass Plate Negative Photography

An Englishman, Frederick Scott Archer, produced the first usable glass photographic negatives in 1848, and made his secret public in 1851. Archer was only one of many unsung tinkerers who struggled to improve on the astonishing inventions of Niepce, Daguerre, and Talbot, who independently discovered the first photographic processes between 1826 and 1839. Archer’s refinement, known as the wet collodion negative, was a technological triumph that overcame the limitations of earlier techniques without sacrificing their greatest advantages: it was nearly as crisp and detailed as a Daguerreotype, but like the positive-negative process invented by Talbot, allowed identical prints to be made in any quantity.

Archer’s process was far from simple. The photographer dissolved gun cotton (explosive cellulose nitrate) in ether, alcohol, and potassium iodide to make the thick, clear, flammable liquid called collodion. This was flowed onto a sheet of glass that was the size of the finished print, from four by five inches or less up to twenty by twenty-four inches. The photographer then tilted the glass from side to side until the entire surface was coated. The plate was plunged into a bath of silver nitrate (which combined with the potassium iodide in the collodion to form light-sensitive silver iodide), then placed in a plate holder, carried to the camera, exposed, and returned to the darkroom or tent for development. All of this had to be done before the collodion dried, or the negative would be botched and the process would have to be repeated; outdoors on a warm Colorado day, a photographer had about six minutes to get the job done.

This complex and rather troublesome technique discouraged all but the most headstrong professional and amateur photographers. Some wet collodion photographers hired assistants to prepare their plates while they focused their cameras and composed their subjects; others set their cameras up in advance. Photographs were made with great deliberation and care, because it was important to get things right the first time out.

A more convenient type of glass negative, the gelatin dry plate, was introduced in the 1870’s and was in general use by 1885. These were coated with a light-sensitive gelatin emulsion that eliminated the dangerous and messy preparations of wet collodion. Even better, dry plates were factory-made, came in a box, and could be stored for months either before or after exposure with little loss of image quality. Amateur photographers loved them because they were easy to use and gave reliable results; hobbyists and dabblers flocked to the new material in record numbers, and amateur photography as we know it was born. George Eastman capitalized on the growing fad by offering his first Kodak cameras and flexible roll films in 1888 and 1889—these inventions revolutionized photography and led to the decline of glass plate photography, which disappeared all together in the mid-1920’s.

The photographs in this collection reflect an important phase of photographic history, but they are much more than technological artifacts. The era of glass plate photography roughly coincided with the first fifty years of Aspen’s history; the surviving glass negatives of Aspen and its people are important records of how things looked and changed during time. They offer us a sense of depth, of continuity, of connection with the past, and place the present and the future in a new and humane perspective.

—Eric Paddock—
Curator of Photography, Colorado Historical Society