Absorbs the ultraviolet rays which often makes outdoor photographs hazy and indistinct. A muliti-purpose fine-weather filter for color as well as black and white films. Also serves as a permanent lens protector. Features: 3-layer HMC multi-coated UV filter using optical glass that is precisely ground and polished for perfect flatness Over 97% average light transmission Heat resistant, high-transparency optical glass Precision milled low-profilealuminum frame.