What is the principle of using photography and recording in movies?

According to the principle of visual persistence, film is a technology that uses photography and recording to record the images and sounds of external things on film (except digital movies), and forms moving images and sounds that can express certain contents on the screen through projection and restoration technology.

Visual persistence is a phenomenon that the vision produced by light on the retina remains for a period of time after the light stops. Its specific application is shooting and projection. The reason is the reaction speed of the optic nerve. Vision is actually imaged by the lens of the eye. Photosensitive cells are very sensitive to light, and light signals are converted into nerve currents, which are transmitted back to the brain to cause human vision. The photosensitivity of photoreceptor cells depends on some photosensitive pigments, and the formation of photosensitive pigments takes some time, forming a mechanism of visual pause.

The origin of the phenomenon of visual persistence

The phenomenon of visual persistence was first used by China people. According to historical records, lanterns were the earliest application of visual persistence. There were lanterns in Song Dynasty, which were called "riding lanterns" at that time. Then the Frenchman Paul Rogay invented the photo disc in 1828, which is a disc with two sides crossed by ropes. One side of the plate is painted with a bird and the other side is painted with an empty cage. When the disc rotates, the bird appears in the cage, which proves that when the eye sees a series of images, it only keeps one image at a time.