The oldest surviving permanent photograph of the image formed in a camera was created in 1826 or 1827 by the French inventor Joseph Nicéphore Niépce.[1] The photograph was produced on a polished
pewter plate. The light-sensitive material was a thin coating of
bitumen, a naturally occurring
petroleum tar, which was dissolved in white petroleum, applied to the surface of the plate and allowed to set before use.
[8] After a very long exposure in the camera (traditionally said to be eight hours, but possibly several days), the bitumen was sufficiently hardened in proportion to its exposure to light that the unhardened part could be removed with a solvent, leaving a positive image with the light regions represented by hardened bitumen and the dark regions by bare pewter.
[8] To see the image plainly, the plate had to be lit and viewed in such a way that the bare metal appeared dark and the bitumen relatively light.
[9]
Niépce had previously experimented with paper coated with silver chloride. Unlike earlier experimenters with silver salts, he succeeded in photographing the images formed in a small camera, producing his first results in 1816, but like his predecessors he was unable to prevent the coating from darkening all over when exposed to light for viewing. As a result, he had become disenchanted with silver compounds and turned his attention to bitumen and other light-sensitive organic substances.
[9]
In partnership, Niépce (in
Chalon-sur-Saône) and
Louis Daguerre (in
Paris) refined the bitumen process,
[10] substituting a more sensitive resin and a very different post-exposure treatment that yielded higher-quality and more easily viewed images. Exposure times in the camera, although somewhat reduced, were still measured in hours.
[9]
In 1833 Niépce died of a stroke, leaving his notes to Daguerre. More interested in silver-based processes than Niépce had been, Daguerre experimented with photographing camera images directly onto a silver-surfaced plate that had been fumed with
iodine vapor, which reacted with the silver to form a coating of
silver iodide. Exposure times were still impractically long.
Then, by accident according to traditional accounts, Daguerre made the pivotal discovery that an invisibly faint latent image produced on such a plate by a much shorter exposure could be "developed" to full visibility by mercury fumes. This brought the required exposure time down to a few minutes under optimum conditions. A strong hot solution of common salt served to stabilize or
fix the image by removing the remaining silver iodide. On 7 January 1839[
citation needed], Daguerre announced this first complete practical photographic process to the French Academy of Sciences[
citation needed], and the news quickly spread. At first, all details of the process were withheld and specimens were shown only to a trusted few[
citation needed],. Arrangements were made for the French government to buy the rights in exchange for pensions for Niépce's son and Daguerre[
citation needed], and then present it to the world (with the
de facto exception of Great Britain) as a free gift[
citation needed],. Complete instructions were published on 19 August 1839[
citation needed],.
So, I know it's possible. Who would have done it? Would it have triggered other inventions ahead of time, like lightbulbs and telephones? Anyway, discuss. 