Daguerreotype
It is said that Daguerre has found the means to collect, on a plate prepared by him, the image produced by the camera obscura, in such a way that a portrait, a landscape, or any view, projected upon this plate by the ordinary camera obscura, leaves an imprint in light and shade there, and thus presents the most perfect of all drawings ... a preparation put over this image preserves it for an indefinite time ... the physical sciences have perhaps never presented a marvel comparable to this one.
A further clue to fixing the date of invention of the process is that when the Paris correspondent of the London periodical "The Athenaeum" reported the public announcement of the daguerreotype in 1839, he mentioned that the daguerreotypes now being produced were of considerably better quality than the ones he had seen "four years earlier".
Louis Daguerre
Daguerreotypes were usually portraits; the rarer landscape views and other unusual subjects are now much sought-after by collectors and sell for much higher prices than ordinary portraits. At the time of its introduction, the process required exposures lasting ten minutes or more for brightly sunlit subjects, so portraiture was an impractical ordeal. Samuel Morse was astonished to learn that daguerreotypes of the streets of Paris did not show any people, horses or vehicles, until he realized that due to the long exposure times all moving objects became invisible. Within a few years, exposures had been reduced to as little as a few seconds by the use of additional sensitizing chemicals and "faster" lenses such as Petzval's portrait lens, the first mathematically calculated lens.