Application of polarization in photography?

Polarizers, also known as PL mirrors, are widely used in photography in the following two aspects:

1, reducing the reflection of nonmetallic surfaces.

For example, taking pictures of fish or other scenery underwater, scenery in glass windows, photos in photo frames, etc. , can effectively reduce the reflection, but the internal scenery is not affected (or reduced).

2. Reduce the influence of fog in the sky and make the sky clearer and bluer.

When using a polarizer, you need to rotate and observe at the same time to achieve the best effect.