The polarizer is a lens manufactured according to the principle of light polarization. It is used to eliminate and filter the direct light in the beam, so that the light can be input into the visual image of the eye on the transmission axis of the normal track, so that the field of vision is clear and natural. Mostly used in sunglasses and camera lenses.
Its working principle is to selectively filter light from a certain direction. By filtering out many polarized light in diffuse reflection, the intensity of light in the sky is reduced, the sky is darkened, and the contrast between blue sky and white clouds is increased. In the actual shooting, you must look at the viewfinder and rotate the front lens. The effect is most obvious when the sky is darkest in the viewfinder, and the difference between the darkest and the most visible is 90 degrees. You can switch to any angle between the darkest and the brightest according to your needs.
The polarizer is composed of a lens body and a rotatable rear seat frame connected to it. The lens body is composed of extremely thin crystal glass as a grating. When rotating, the grating of the polarizer blocks the polarized light that is not parallel to it. Therefore, the polarizer can control and selectively record the amount of reflected light parallel to it (this reflected light is polarized light). This is the reason why the polarizer can eliminate or reduce the reflection of non-metallic surfaces. But most polarizers are a little bit blue. At the same time, part of the unpolarized light in the same direction as the vibration of the polarized light is blocked when used for shooting. In order to avoid the color of the picture being too flat, it is generally necessary to increase the exposure by more than one level.