Daguerreotype
Morse met the inventor of the daguerreotype, Louis-Jacques-Mande Daguerre, in Paris in January 1839 when Daguerre's invention was announced [2]. While the daguerreotype fascinated Morse, he was concerned about how the new invention would compete with his telegraph. However, Morse's viewing of the daguerreotype alleviated his fears when he saw how revolutionary its technology was. Morse wrote a letter to his brother Sidney describing Daguerre's invention, which Sidney then published in the New-York Observer on April 20, 1839. While this was not the first report of the daguerreotype to appear in America, it was the first in-person report to appear in the United States.
History of photographic lens design
Charles Chevalier's Paris optical firm produced lenses for both Niépce and Daguerre for their experiments in photography. In 1829, Chevalier created an achromatic lens (a two-element lens made from "crown glass" and "flint glass") to cut down on chromatic aberration for Daguerre's experiments. Chevalier reversed the lens (originally designed as a telescope objective) to produce a much flatter image plane and modified the achromat to bring the blue end of the spectrum to a sharper focus. Reversing the lens caused severe spherical aberration so a narrow aperture stop was necessary in front of the lens. On 22 June 1839, Daguerre contracted Alphonse Giroux (France) to manufacture his daguerreotype apparatus. The Giroux Le Daguerreotype camera used an almost 16-inch (40 cm) focal length reversed achromatic lens with a f/16 stop in front of it made by Chevalier to take 6½×8½ inch (about 16.5×21.5 cm) images.