The first photographic photo in history was taken on asphalt in 1826 by the Frenchman Joseph Nicéphore Nièpce (1765-1833), but it did not He died after finally perfecting this technique; his partner, the French painter Louis Jacques Mand Daguerre (1789-1851), invented the daguerreotype method based on his results, and in 1839 August In March, the French government announced that it had obtained a patent for photography. Today's Polaroid cameras still use a photography method similar to the daguerreotype.
When taking pictures, light enters the cassette through a small hole (more often a lens group small hole imaging principle), and is imaged on the medium on the back of the cassette (relative to the direction of light incidence). Depending on the actual light intensity and the photosensitivity of the medium, the required illumination time is also different. During the illumination process, the medium is exposed to light. After the photography is completed, the image information stored in the medium must be converted and read again by the human eye. The specific method depends on the photosensitive means and medium characteristics. For film cameras, there are chemical processes such as fixing, development, and amplification. For digital cameras, a processor is needed to calculate the data and then output it through electronic devices.