Professional High Definition 77mm Clear Digital Ultra Violet UV Filter for Canon Telephoto EF 400mm f/5.6L USM Absorbs UV light, which often makes outdoor photographs hazy and indistinct Clear filter provides no additional coloration or contrast, allowing you to pair this filter with others Works as general protection filter to reduce dust, moisture, and scratches from reaching lens elements Multi-coating helps to reduce flare, ghosting, and reflections on the filter surface for higher light transmission of approximately 96%, resulting in greater contrast and color fidelity Crafted from optical glass and a precision milled aluminum frame