Daguerreotype:
The daguerreotype is an early type 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 vapor. In later developments bromine and chlorine vapors were also used, 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.

While the daguerreotype was not the first photographic process to be invented, earlier processes required hours for successful exposure, making daguerreotype 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, applying and extending a discovery by Johann Heinrich Schultz (1724): a silver and chalk mixture darkens when exposed to light. The French Academy of Sciences announced the daguerreotype 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.