1. Polarizer has linear polarizer (line deviation) and circular polarizer
(Circularly biased), the method of use and the same effect; but the circular deviation allows the light to pass through the filter and is circular rather than linear, especially suitable for cameras with an autofocus system.
When using a single-lens reflex machine, the circular polarizer ensures focus accuracy because a reflective lens is used inside the camera.
A cheaper line bias may affect the autofocus of some cameras during use, so if you use a polarizer on a digital camera, you need to use a circle.
2. Polarizers are generally thicker. It is best not to use them with other filters. Otherwise, it is easy to form black corners in the picture.
3. The polarizer itself absorbs about 75% of the light. If it is used on a cloudy day or when using a small aperture, it is best to stabilize the body with a tripod. Since digital cameras use TTL metering, there is no need to compensate for exposure due to reduced light input.