What's the use of camera lens accessories?

1. lens cover: protects the lens from scratches and pollution.

2. Hood: to prevent light from shining directly on the lens, causing glare.

3. Filter: UV is the protection and protection mirror; Gradient mirror-used for sunrise and sunset shooting with too strong light ratio; Reduction mirror-used to photograph streams and waterfalls to make them silky smooth; Close-ups-used for macro photography; Polarizer-used to reduce reflection, can also make the blue sky deeper and white clouds more prominent: color mirror-color temperature corrected in film age; Starlight mirror-let the point light source appear star awn; Soft lens-make the picture soft and hazy.