Cameras, waterproof digital cameras, and various types of cameras work on the same basic principle: converting optical image signals into electrical signals for easy storage or transmission. When we shoot an object, the reflected light on the object is collected by the camera lens and focused on the receiving surface of the camera device (such as the target surface of the camera tube). Then, the light is converted into electrical energy through the camera device, resulting in a "video signal". The photoelectric signal is very weak and needs to be amplified through a preamplifier circuit, processed and adjusted through various circuits. The final standard signal can be recorded on recording media such as a video recorder, or transmitted through a propagation system or displayed on a monitor.