Heliography (in French, héliographie) is the photographic process invented by Joseph Nicéphore Niépce around 1822, which he used to make the earliest known surviving photograph from nature, View from the Window at Le Gras (1826 or 1827). The process used Bitumen of Judea, a naturally occurring asphalt, as a coating on glass or metal. It hardened in proportion to its exposure to light. When the plate was washed with oil of lavender, only the hardened areas remained.
The word has also been used to refer to other phenomena: for description of the sun (cf. geography), for photography in general, for signalling by heliograph (a device less commonly called a heliotrope or helio-telegraph), and for photography of the sun.
- "The First Photograph — Heliography". Retrieved 2009-09-29.
from Helmut Gernsheim's article, "The 150th Anniversary of Photography," in History of Photography, Vol. I, No. 1, January 1977: ...In 1822, Niépce coated a glass plate... The sunlight passing through... This first permanent example... was destroyed... some years later.
- Descriptions of the sun, photography in general, and signalling by heliotrope: Oxford English Dictionary 2nd ed. (1989) s.v. "Heliography". Photography of the sun: As used by and in discussion of Hiroshi Yamazaki.
- Art & Architecture Thesaurus, s.v. "heliography". Accessed 10 December 2007.
- Harry Ransom Center. The University of Texas at Austin. The First Photograph. Accessed 10 December 2007.
- An Improved Method in the Art of Signalling for Military & Scientific Purposes (1887). Accessed 1 June 2008.