The UV Protector helps protect your camera or camcorder lens against dust, moisture, fingerprints, scratches, and damage while providing the basic protection against UV light. It can be kept on your camera lens at all times. These filters are used by many photographers to protect the front element of their lens from abrasions, dust, and moisture. They also have a very subtle warming effect, which can be useful to counter the "cool" colors you sometimes get in bright sun or in shade. They're available in sizes to fit most EF lenses.