Why can we see the scene clearly in the dark with a night vision device?
Wanting to see the scene in the dark, just relying on the naked eye is extremely difficult. But thanks to night vision devices, even if there is no light or only a little light, it is still possible to see the scene in such a state. Commonly used night vision device cameras are of two types: low-light night vision devices and infrared night-vision cameras.
Only a little moonlight dims and shadows increase the micro-optical night vision device camera (weak light) in a night. Through photoelectric conversion and magnification, it can enhance the weak light rays reflected from the scene. The image enhancement shadow is made up of the three-level magnification plate, magnifying up to a million times, enough to reproduce the scene in a dimly clean environment. In the state of absolutely no light, the infrared night vision device machine is very effective.
Infrared rays are not only visible light, invisible to the naked eye, but also have light characteristics. Objects in the natural world can emit infrared rays with a zero or higher (i.e., -273.15 ° C or higher). The infrared image variation shade in the infrared night vision device camera can receive infrared rays through photoelectric conversion and magnification to make the scene visible. It is a passive infrared night vision device machine that must rely on the radiating scene’s infrared rays to see the dark scene. There is also an active infrared night vision device machine. It can emit infrared rays and then pick up infrared rays that are reflected from a scene. This can greatly enhance scene clarity.
Infrared night vision device machines can also “see” unmistakably in dense fog environments, very close vision, because infrared rays have a quite strong penetrating ability, and can transmit to very long distances. With infrared night vision device machines, without headlights on, drivers can also drive cars fast in the dark. In terms of military reconnaissance, crime is prevented from the police, even observing animals and plants in the dark, the infrared night vision device machine has even more special use.