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.
Louis Daguerre
When the first reports of the French Academy of Sciences announcement of Daguerre's invention reached Talbot, with no details about the exact nature of the images or the process itself, he assumed that methods similar to his own must have been used, and promptly wrote an open letter to the Academy claiming priority of invention. Although it soon became apparent that Daguerre's process was very unlike his own, Talbot had been stimulated to resume his long-discontinued photographic experiments. The "developed out" daguerreotype process only required an exposure sufficient to create a very faint or completely invisible latent image which was then chemically developed to full visibility. Talbot's earlier "sensitive paper" (now known as "salted paper") process was a "printed out" process that required prolonged exposure in the camera until the image was fully formed, but his later calotype (also known as talbotype) paper negative process, introduced in 1841, also used latent image development, greatly reducing the exposure needed, and making it competitive with the daguerreotype.