Daguerreotype photography was invented by the French photographic pioneer Louis Daguerre (1789-1851) and was made public in 1839. In the Daguerreotype proces a picture made on a silver surface sensitized with iodine was developed by exposure to mercury vapour. Daguerre granted the right to make and sell daguerreotype cameras to a relative of his, Alphonse Giroux of Paris. Photography thus became available to the general public in 1839 and this was the first commercially available camera, which produced the first distinctive photographic positives. It took pictures 8.5 x 6.5 inches (21.6cm x 16.5cm), a size which became known as whole-plate when later cameras were built to take photographs a fraction of the size.
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