camera -lens hood utilities
1. Backlighting, when sidelighting or flash photography, to prevent the entry of non-imaging light to avoid the mist.
2.between the sidelighting and in the cis-ray photography, the scattering can be avoided around the light into the lens.
3. In the light or night photography photography, the interference can be avoided around the light into the lens.
4. To prevent accidental damage to the lens, they could also avoid inadvertently touching the lens surface of the fingers, but also to some extent for the lens block wind, rain and snow.