What is heliography? Definition and basic principles
Heliography is the oldest known photographic process. Developed by the French inventor Joseph Nicéphore Niépce in the early 19th century, it underlies the world’s first permanently preserved photograph. Anyone asking “What is heliography?” finds the answer in its etymology: the term comes from Greek and means “drawing with the sun.”
Definition of heliography
Heliography is a process in which sunlight hardens a layer of bitumen applied to a metal plate. The more exposed areas harden, while the less exposed areas remain soft and can be washed away.
What remains is a fixed image—permanent, irreversible, and shaped solely by light and time
How does heliography work?
A metal plate—usually made of zinc, tin, or copper (I sometimes also use aluminum)—is coated with a thin layer of bitumen dissolved in lavender oil. The plate is then exposed to sunlight over an extended period: several hours or even days.
Where light strikes the surface, the bitumen hardens. The softer, unexposed areas are then washed away using a mixture of lavender oil and white spirit.
The result is a visible, permanently fixed image.
What distinguishes heliography?
In contrast to modern photography, heliography operates with extreme slowness. Exposure times can last hours or even days—time itself becomes a physical component of the image.
Each heliographic image is unique and cannot be reproduced. There are no duplicates. The image exists only once—fixed in matter.
Who invented heliography?
Heliography was developed by Joseph Nicéphore Niépce (1765–1833), a French inventor from Saint-Loup-de-Varennes.
After years of experimenting with various light-sensitive materials, he discovered that bitumen—a natural asphalt—could permanently fix an image.
In 1827, he produced the first surviving photograph to this day: a view from the window of his estate, Le Gras, with an exposure time of several days.
Why is heliography still relevant today?
Heliography is not merely a historical curiosity. The questions it raises—about duration, materiality, and the nature of images—remain highly relevant in a world of instantaneous digital photography.
In the Heliography Project 1827–2027, the process is reactivated in order to interrogate contemporary visual culture: What does it mean to produce images through time rather than through speed?
→ To the Heliography Project 1827–2027