The first photograph in history was taken on asphalt in 1826 by a Frenchman, joseph Nicephore Niepce (1765- 1833), but he died before the technology was finally perfected. His partner, the French painter Louis Jacques Manda Daguerre (1789- 185 1), invented the silver plate photography method based on his achievements, and in August 1839, the French government announced that he had obtained the photography patent. Today's Polaroid cameras still use a photographic method similar to the silver plate method.

When taking pictures, the light enters the cassette through a small hole (more often, it is the imaging principle of the small hole of the lens group) and is imaged on the medium on the back of the cassette (relative to the incident direction of light). According to the actual light intensity and the photosensitive ability of the medium, the required light time is also different. In the process of illumination, the medium is irradiated by light. After photography is completed, the image information stored in the medium must be read by human eyes again through conversion. The specific method depends on the photosensitive means and medium characteristics. For film cameras, there will be chemical processes such as fixing, developing and enlarging. For a digital camera, it needs a processor to calculate the data and then output it through electronic equipment.