Photography moves from wet plates to dry
There’s no denying that the wet plate process was not easy. It took considerable time, planning, effort, money, supplies, and proper logistics to execute and to top it off, the chemicals and fumes from the alcohols and ethers were health hazards. In 1860, a French scientist called Taupenot produced the first ever collodion dry plates. Since they didn’t require the whole wet plate prepping process, photographers were attracted to them, however, their flaws were quickly discovered in that these new collodion dry plates were 6 times less sensitive than wet plates. Fairly soon after, in 1864, Sayce and Bolton added bromide to the solution which cut the exposure time in half for the dry plates. They still required longer exposures than the wet plate.
As more and more improvements chipped away the dry plate’s flaws, the first easily usable dry plates emerged in 1878. These dry plates now incorporated a silver bromide emulsion that used a gelatin binder to allow the emulsion to adhere to the plate. The sensitivity of these new plates jumped to about 10 times that of the wet plate. Initially, photographers had a hard time getting used to the incredibly short exposure times. Photographers soon became more adventurous with their work thanks to the advantages of not having to make their own plates as well as not needing to immediately process the exposed plate. In the 1870’s a German photochemist, Hermann Wilhelm Vogel was working on the problem of photographic emulsions only being sensitive to the blue-violet and ultraviolet part of the spectrum. Vogel discovered that he could add different dyes to the emulsion which would increase the sensitivity range of that emulsion. By 1884, Vogel and Johann Obernetter had developed the first commercially available gelatin silver dry plate that was sensitive to the entire visible light spectrum, minus red. These plates were termed to be orthochromatic.
Their plates had some of their own issues such as fogginess and diminished sensitivity. Photographically, it was more accurate and precise with the black, white, and grey tones it replicated. Vogel ended up becoming the first professor of photography at the Institute of Technology in Berlin and worked with his students to develop the first emulsions that were sensitive to all visible wavelengths (including red.) These were named panchromatic plates. Their work laid a lot of groundwork for the birth of color photography as well and I’ll touch on more of that in another post.