Daguerreotype
Invented by Louis-Jacques-Mandé Daguerre and introduced worldwide in 1839, daguerreotype was almost completely superseded by 1860 with new, less expensive processes yielding more readily viewable images. In the late 20th century, there was a revival of daguerreotypy by a small number of photographers interested in making artistic use of early photographic processes.
Daguerreotype
The written contract drawn up between Nicéphore Niépce and Daguerre includes an undertaking by Niépce to release details of the process he had invented – the asphalt process or heliography. Daguerre was sworn to secrecy under penalty of damages and undertook to design a camera and improve the process. The improved process was eventually named the physautotype.