The first permanent photograph was an image produced in 1826 by the French inventor Joseph Nicéphore Niépce. His photographs were produced on a polished pewter plate covered with a petroleum derivative called bitumen of Judea, which he then dissolved in white petroleum. Bitumen hardens with exposure to light. The unhardened material may then be washed away and the metal plate polished, rendering a positive image with light regions of hardened bitumen and dark regions of bare pewter. Niépce then began experimenting with silver compounds based on a Johann Heinrich Schultz discovery in 1727 that silver nitrate (AgNO3) darkens when exposed to light.
In partnership, Niépce (in Chalon-sur-Saône) and Louis Daguerre (in Paris) refined the existing silver process. In 1833 Niépce died of a stroke, leaving his notes to Daguerre. While he had no scientific background, Daguerre made two pivotal contributions to the process. He discovered that exposing the silver first to iodine vapour before exposure to light, and then to mercury fumes after the photograph was taken, could form a latent image. Bathing the plate in a salt bath then fixes the image.
On January 7, 1839 Daguerre announced that he had invented a process using silver on a copper plate called the daguerreotype, and displayed the first plate. The French government bought the patent and almost immediately (on August 19 of that year) made it public domain.
In 1832, French-Brazilian painter and inventor Hercules Florence had already created a very similar process, naming it Photographie.
Talbot worked on perfecting his own process; in 1839 he acquired a key improvement, an effective fixer, from John Herschel, the astronomer, who had previously showed that hyposulfite of soda (also known as hypo, or now sodium thiosulfate) would dissolve silver salts. Later that year, Herschel made the first glass negative.
By 1840, Talbot had invented the calotype process. He coated paper sheets with silver chloride to create an intermediate negative image. Unlike a daguerreotype, a calotype negative could be used to reproduce positive prints, like most chemical films do today. The calotype had yet another distinction compared to other photographic processes of the day, in that the finished product lacked fine clarity due to its translucent paper negative.
This was seen as a positive attribute for portraits because it softened the appearance of the human face. Talbot patented this process, which greatly limited its adoption. He spent the rest of his life in lawsuits defending the patent until he gave up on photography. Later George Eastman refined Talbot’s process, which is the basic technology used by chemical film cameras today.
Hippolyte Bayard had also developed a method of photography but delayed announcing it, and so was not recognized as its inventor.
In 1839, John Herschel made the first glass negative, but his process was difficult to reproduce. Slovene Janez Puhar invented a process for making photographs on glass in 1841; it was recognized on June 17, 1852 in Paris by the Académie Nationale Agricole, Manufacturière et Commerciale. In 1847, Nicephore Niépce’s cousin, the chemist Niépce St.
Victor published his invention of a process for making glass plates with an albumen emulsion; the Langenheim brothers of Philadelphia and John Whipple of Boston also invented workable negative-on-glass processes in the mid 1840s.
In 1851 Frederick Scott Archer invented the collodion process. Photographer and children’s author Lewis Carroll used this process.