Solarigraphy, is a photographic method for recording the paths of the Sun, using a fixed pinhole camera and exposing photographic paper for an absurdly long amount of time (sometimes half a year).
The picture will appear without developing photographic paper with any kind of chemicals. Exposured paper is scanned in darkness and developed in Photoshop. All the cameras are very low tech, cheap boxes, canisters or film cans.
This solargraph is the result of a six-month exposure of an area in Helsinki taken with a self-built pinhole camera from a balcony. Solargraphy by Tarja Trygg.
Solargraphy . com