出典:Wiktionary
heliography (uncountable)
出典:Wikipedia
出典:『Wikipedia』 (2010/11/20 11:23 UTC 版)
Heliography (in French, héliographie) is the photographic process invented by Joseph Nicéphore Niépce around 1822, which he used to make the earliest known permanent photograph from nature, View from the Window at Le Gras (c. 1826). The process used bitumen, as a coating on glass or metal, which hardened in relation to exposure to light. When the plate was washed with oil of lavender, only the hardened image area remained.