Bitumen of Judea
Bitumen of Judea, or Syrian asphalt,[1] is a naturally occurring asphalt that has been put to many uses since ancient times. It is now best known as the light-sensitive material in what is widely accepted as the first complete photographic process, i.e., one capable of producing durable light-fast results. The technique was developed by French scientist and inventor Nicéphore Niépce in the 1820s. In 1826 or 1827, he applied a thin coating of the tar-like material to a pewter plate and took a picture of parts of the buildings and surrounding countryside of his estate, producing what is usually described as the first photograph. More accurately, it is the oldest known surviving camera photograph. The plate had to be exposed in the camera for at least eight hours and probably for several days. The bitumen, initially soluble in spirits and oils, was hardened and made insoluble (probably polymerized) in the brightest areas of the image. The unhardened part was then rinsed away with a solvent.[2][3][4]
The bitumen used by Niépce actually came from a mine in France, not from Judea.
Niépce's primary objective was a photoengraving or photolithography process, and bitumen, superbly resistant to strong acids, was in fact later widely used as a photoresist in making printing plates for mechanical printing processes. The surface of a zinc or other metal plate was coated, exposed, developed with a solvent that laid bare the unexposed areas, then etched in an acid bath, producing the required surface relief.[5]
References
- ↑ History of Polymeric Composites, edited by Raymond Benedict Seymour, Rudolph D. Deanin, p319
- ↑ Niépce Museum history pages
- ↑ The First Photograph (Harry Ransom Center, University of Texas at Austin)
- ↑ Hirsch, Robert. Seizing the Light: A History of Photography. New York: McGraw-Hill, 2000. Print.
- ↑ Beaumont Newhall, "The History of Photography," 2001, p 14. ISBN 0-87070-381-1
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