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Daguerre's early photographs had to be exposed for a very long time, which made portraiture almost impossible. They could also only produce one copy, since the glass plate that took the photograph, was also the image which appeared as the final product. Exposure times were shortened by making in use of a combination of silver iodide and silver bromide. The production of large numbers of prints from one photograph required a different process, however, one which was invented by an Englishman called William Henry Fox Talbot. You can read his story on the next page. You can find out more about Niepce at Niepce.com, and about Daguerre at A History of Photography. |
In
the 1820s, a Frenchman called Joseph Nicéphore Niepce was experimenting
with ways of making a permanent record of the image seen in a camera obscura
(what we would now call a pinhole camera). Using a glass place coated
in bitumen, he eventually succeeded in producing a very faint print of
the view from a window of his house in 1827.
Meanwhile,
Louis Jacques Mandé Daguerre was also trying experiments to capture
the camera obscura image. He heard of Niepce's work, and spent two years
collaborating with him, before Niepce died in 1829. Daguerre continued
his work, using silver iodide to coat his plates, rather than bitumen.
When the exposed plates were treated with mercury vapour, an image appeared,
which was made permanent by removing the excess silver iodide. The photographs
which were produced by this process were called 'daguerrotypes' - you
can see an example by opening this