Why does photography make the sky look a little white instead of blue? No one can make it look blue! I seek advice and master!

The first reason: the atmosphere itself is dusty, and the sky must be gray. The sky in mountainous areas or high altitude areas will be much bluer than that in cities. Such as the Qinghai-Tibet Plateau.

Reason 2: I didn't use a polarizer when shooting. After using a polarizer, the disorderly reflected light will be eliminated and the sky will turn blue.

Reason 3: The photos have not been post-processed. It will be much brighter after increasing saturation.

Reason 4: The shooting time is wrong. The sunlight in the photo is sidelight. The sky part of this light is easy to fill, not too blue.