Daguerreotype Half-Plate - In its Napoleon III Frame

Daguerreotype half-plate, portrait of a man of letters in its Napoleon III frame.

The daguerreotype was the first photographic process, developed by Nicéphore Niépce and later Louis Daguerre, and introduced to the world (except the United Kingdom) by France in 1839. It is both a negative and a positive, hence its characteristic mirror effect. In the 19th century, they were also poetically called "mirrors that remember."

Given the cost and technical difficulties, it will only be used for about ten years in France and will be replaced by other processes.

However, there are later daguerreotypes, particularly American or Anglo-Saxon ones.