Daguerreotype

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The daguerreotype is one of the earliest types of photograph in which the image is exposed directly onto a mirror-polished surface of silver bearing a coating of silver halide particles deposited by iodine vapour. In later developments bromine and chlorine vapours were also utilized, resulting in shorter exposure times. Unlike later photographic processes that supplanted it, the daguerreotype is a direct positive image making process with no "negative" original.

1 History
2 Dageurreotype process
3 Proliferation
4 Demise
5 Living art
6 References
7 External links

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History

While the daguerreotype was not the first photographic process to be invented, earlier processes required hours for successful exposure, making dageurreotype the first commercially viable photographic process and the first to permanently record and fix an image with exposure time compatible with portrait photography.

The daguerreotype is named after one of its inventors, French artist and chemist Louis J.M. Daguerre, who announced its perfection in 1839 after years of research and collaboration with Joseph Nicephore Niepce The French Academy of Sciences announced the process on January 9 of that year.

Daguerre's French patent was acquired by the French Government. On August 19, 1839 the French Government announced the invention a gift "Free to the World". Almost simultaneously in England, Miles Berry, acting on Daguerre's behalf, had obtained a patent for the daguerreotype process on August 14, 1839.

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Dageurreotype process

The daguerreotype was a positive-only process allowing no reproduction of the picture. Preparation of the plate prior to image exposure resulted in the formation of a layer of photo-sensitive silver halide, and exposure to a scene or image through a focussing lens formed a latent image. The latent image was made visible, or "developed", by placing the exposed plate over a slightly heated (about 75°C) cup of mercury.

The mercury vapour condensed on those places where the exposure light was most intense, in proportion with the areas of highest density in the image. This produced a picture in an amalgam, the mercury vapour attaching itself to the altered silver iodide. Removal of the mercury image by heat validates this chemistry. The developing box was constructed to allow inspection of the image through a yellow glass window while it was being developed.

The next operation was to "fix" the photographic image permanently on the plate by dipping in a solution of hyposulphite of soda—known as "fixer" or "hypo". The image produced by this method is so delicate it will not bear the slightest handling. Practically all daguerreotypes are protected from accidental damage by a glass-fronted case. It was discovered by experiment that treating the plate with heated gold chloride tones and strengthens the image, although it remains quite delicate and requires a well-sealed case to protect against touch as well as oxidation of the fine silver deposits forming the blacks in the image. The best-preserved daguerreotypes dating from the nineteenth century are sealed in robust glass cases evacuated of air and filled with a chemically-inert gas, typically nitrogen.

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Proliferation

Daguerreotype photography spread rapidly across the United States but not in England, where Louis Daguerre controlled the practice with a patent. Richard Beard, who bought the English patent from Miles Berry in 1841, closely controlled his investment, selling licenses throughout the country and prosecuting infringers.

In the early 1840s the invention was introduced in a period of months to practitioners in the United States by Samuel Morse, inventor of the telegraph code. A flourishing market in portraiture sprang up, predominantly the work of itinerant practitioners who travelled from town to town. For the first time in history people could obtain an exact likeness of themselves or their loved ones for a modest cost, making portrait photographs extremely popular with those of modest means. Their wealthy counterparts continued to commission painted portraits by fine artists, considering the new photographic portraits inferior in much the same way their ancestors had viewed printed books as inferior to hand-scribed books centuries earlier. In some ways they were right, in other ways wrong; the vast bulk of 19th century portrait photography effected by itinerant practitioners was of inferior artistic quality, yet the work of many portrait painters was of equally dubious artistic merit, and although photographic images were monochrome they offered a technical verisimilitude to the sitter no portrait painter could achieve.

The first erotic photographs and the first experimenters in stereo photography also utilized daguerreotypes.

The daguerreotype is commonly, erroneously, believed to have been the dominant photographic process into the late part of the 19th century. Evidence from the period proves it was only in widespread use for approximately a decade before being superseded by other processes:

The Calotype, introduced in 1841. A negative-positive process using paper, and later glass negatives, printed on sensitized paper known as the albumen print, used extensively in the American Civil War
The Ambrotype, introduced in 1854; a positive image on glass, with a black backing
The Tintype or Ferrotype; an image on asphaltum-coated iron plates.

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Demise

The intricate, complex, labor-intensive daguerreotype process itself helped contribute to the rapid move to the ambrotype and tintype. The resulting reduction in economy of scale made daguerreotypes expensive and unaffordable for the average person. Another factor that went against the dageurreotype was the typical exposure time, requiring the subject(s) to remain posed perfectly still for 60 to 90 seconds.

The daguerreotype's lack of a negative image from which multiple positive "prints" could be made was a limitation also shared by the tintype and ambrotype, and was not a factor in the daguerreotype's demise until the introduction of the calotype. Unlike film and paper photography however, a properly sealed daguerreotype can potentially last forever.

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Living art

Antique items are avidly collected. Some daguerreotypes—such as those by Southworth & Hawes of Boston, or George S. Cook of Charleston, South Carolina—are considered masterpieces in the art of photography.

Dageureotypey continues to be practiced by enthusiastic photographers to this day, although in much smaller numbers; there are thought to be fewer than 100 worldwide. Its appeal lies in the "magic mirror" effect of light reflected from the polished silver plate through the perfectly sharp silver image, and in the sense of achievement derived from the dedication and hand-crafting required to make a daguerreotype.

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