On August 19, 1839, details of Louis Daguerre's first practical photographic process were released in Paris. From the article:
"Aug. 19, 1839: Photography Goes Open Source
__1839: __With a French pension in hand, Louis Daguerre reveals the secrets of making daguerreotypes to a waiting world. The pioneering photographic process is an instant hit.
Using chemical reactions to make images with light was not quite new. Doing it fast was. Inventor Joseph Nicéphore Niepce created a rough image using silver salts and a camera obscura, or "dark box," in 1816. The image faded away quickly.
Another decade of work led to the first permanent photographic image, when Niepce fixed a shot of his courtyard onto a pewter plate. The exposure took eight hours in bright sunlight. Niepce continued researching in hopes of making the process faster and more practical.
Daguerre was a successful commercial artist hoping to increase the realism of his giant diorama paintings, some of them 70 feet long by 45 feet high. When using a camera obscura to sketch the outlines (or cartoons) for his paintings, he thought it would be better to create images directly with the camera. He began experimenting.
Daguerre's optician told him about Niepce's work. Daguerre and Niepce began a correspondence that turned into a partnership in 1829. Niepce died in 1833, and his son Isidore labored on. But it was Daguerre's advances with silver-plated copper sheets, iodine and mercury that cut exposure time down to minutes and created positive rather than negative images.
Daguerre was unable to sell his process by subscription, but it caught the interest of François Arago, perpetual secretary of the French Academy of Sciences. It was under the auspices of the academy that Daguerre first displayed his daguerreotypes to the public on Jan. 9, 1839. They created a sensation.
Arago used the buzz to lobby the French Parliament to grant pensions to Daguerre and Isidore Niepce, so they could make all the steps of the new process public and France would "then nobly give to the whole world this discovery which could contribute so much to the progress of art and science."
Parliament agreed: Daguerre got 6,000 francs (about $30,000 in today's money) per year and Niepce 4,000 francs per year. With a flurry of advance publicity, Daguerre and Arago made the technical details public on Aug. 19. They also described Niepce's earlier processes, heliography and the physautotype, but presented the daguerreotype alone as having a future.
And what a future! Within days, opticians and chemists in Paris sold out of the supplies needed to make cameras and plates. Improvements to the process followed within weeks. Daguerre's instruction manual was translated into a dozen languages within months.
No one wanted to have a portrait painted; everyone wanted a daguerreotype. Studios opened all over Paris. "Daguerreotypomania" spread from Paris to the rest of France, then across the continent, across the channel to England and across the Atlantic to America.
Daguerre did more research, but not to much effect, as many innovators surpassed him. He died in 1851. Another decade and the daguerrotype would be largely supplanted by the albumen print, which made images on paper instead of metal."