The first permanent photograph was made in 1822 by a French inventor, Joseph Nicéphore Niépce, building on a discovery by Johann Heinrich Schultz (1724): that a silver and chalk mixture darkens under exposure to light. Niépce and Louis Daguerre
refined this process. Daguerre discovered that exposing the silver
first to iodine vapor, before exposure to light, and then to mercury
fumes after the photograph was taken, could form a latent image; bathing
the plate in a salt bath then fixes the image. These ideas led to the
famous daguerreotype.
The daguerreotype had its problems, notably the fragility of the
resulting picture, and that it was a positive-only process and thus
could not be re-printed. Inventors set about looking for improved
processes that would be more practical. Several processes were
introduced and used for a short time between Niépce's first image and
the introduction of the collodion process in 1848. Collodion-based wet-glass plate negatives with prints made on albumen paper remained the preferred photographic method for some time, even after the introduction of the even more practical gelatin process in 1871. Adaptations of the gelatin process have remained the primary black-and-white photographic process to this day, differing primarily in the film material itself, originally glass and then a variety of flexible films.
History Photograph
07.22 |
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History Photograph
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