Do I have to use a filter to shoot the scenery?

In my opinion, polarizer is the most important filter in landscape photography. Many photographers know how to use polarizers to make the blue sky bluer and eliminate the reflection of glass, water and metal, but in fact polarizers can do more. Even on cloudy days, polarizers have obvious effects. Although it can't turn the gray sky into blue, it can make the color stronger by removing the reflection from the surface. For example, on a cloudy day, every leaf, every piece of glass and every slippery stone will reflect some light from the gray sky. These reflections obviously lighten the color. Put a polarizer in front of the camera, turn it and you will find that the color becomes stronger. Try shooting the same scene with or without a polarizer, and you will find amazing differences in the final photo.