Solargraphy is a technique in which a homemade pinhole camera can be used to expose the photosensitive photographic paper for a long exposure time. Depending on the length of the exposure, the resulting image shows the path of the sun across the sky from dawn to dusk, but also from north to south (or vice versa) between the solstices. Each streak of light in the solargraphic image represents one day. Missing light streaks indicate that the sun is obstructed by cloud cover. This method allows the use of very long exposure times: several weeks, few months, or even years.