Daguerreotype process

The first permanent images were obtained by the French landowner . N. Niepce using bitumcn-coated pewter (bitumen hardens when expo.sed to light for several hours and the unexposed portions can then be dissolved away in oil of turpentine). He then helped the portrait painter, L. J. M. Daguerre, to perfect the daguerreotype process which utilized plates of copper coated with silver sensitized with iodine vapour. The announcement of this process in 1839 was greeted with enormous enthusiasm but it. suffered from the critical drawback that each picture was unique and could not be duplicated. 

The daguerreotype process may be considered the most perfect of all the photographic processes at present known for certainly it stands unequalled for microscopic perfection of detail, modulation of shade, and beauty of half-tone nor is this superiority to bo wondered at whan it is considered that the chemicals ore applied in the form of impalpable vapor, and that the tablet is a highly polished metal plate while in other processes the chemicals are either contained in a coarse material like paper, or else in a gummy film, which is spread Upon glass, leather, or enamel. -... 

BECQUEREL EFFECT, A photographic effect discovered by E, Becquerel (1895). Experimenting with the daguerreotype process. Becquerel found that a plate will produce a direct (positive) image if exposed first to diffuse daylight. See also Photochemistry and Photolysis and Photography and Imagery. 

Dasuerre, Louls-Jacques-Mande (1787-1851) French inventor who discovered that silver iodide, freshly prepared in the dark, was sensitive to light and that an image projected onto a surface covered with this compound could be developed chemically and then fixed to form a permanent photograph. This was the daguerreotype process, the first successful and commercially viable photographic method. 

Daguerreotypes are permanent when the manipulation Is properly performed, the plate thoroughly washed, and carefully sealed up in an air-tight case. In order to avoid the reversion of the image, a reflector must be us d in front of the lens, an expedient which is not necessary in any other process. 

This was the very first toning approach for photographic prints and was taken directly from the technique used to gild daguerreotypes except that in that technique heat was applied to the underside of the plate during the process. 

Daguerreotype (Jacques Daguerre) Improving on the discoveries of Joseph Nicephore Niepce, Daguerre develops the first practical photographic process, the Daguerreotype. 

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