Heliography

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.