Polarizer knowledge introduction

Date:2017-11-08 Author:admin Click:

A polarizer, also called a polarizer, or PL lens for short, is a color filter. The excellent function of a polarizer is that it can selectively pass light that vibrates in a certain direction. It is commonly used in color and black and white photography to eliminate or weaken strong reflections on non-metallic surfaces, thereby eliminating or reducing light spots. For example, in scenery and landscape photography, it is often used to express the texture of objects in strong reflections, highlight the scenery behind the glass, darken the sky, and express blue sky and white clouds.

According to different mechanisms for filtering polarized light, polarizers can be divided into two types: circular polarizers (CPL) and linear polarizers (LPL).

偏振镜结构示意图.png

Schematic diagram of polarizer structure

The role of polarizers

1. Reduce and eliminate the reflection of light on the surface of objects, such as the reflection of metal, water, and glass. For example, if you want to shoot something in a shop window, you must reduce the reflection of glass. If you want to shoot underwater objects, you must try to reduce the reflection on the water surface.

2. Darken the sky and set off the shape of the clouds.

3. Making the color thicker actually lowers the brightness.

4. Extend the exposure time.

When using automated technology to inspect products, images become the most critical step in the entire inspection process. The use of polarizing plates can reduce the characteristics of light reflection, which can greatly improve the imaging quality of some machine vision projects and achieve the purpose of detection. The following is the effect of the polarizer when testing the aluminum foil packaging of tablets:

1 (2).png