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. Hardened Glass: Hardened optical glass that has 4 times the breaking strength in ANSI standardized testing (ANSI Z80.3 : 2001) where a steel balls of varying size and weight were dropped from a height of 50 inches onto the glass. Hardened 8 Layer Waterproof Multi-Coating that is Scratch & Stain Resistant: Newly developed industry leading 8-layer multi-coating yields an average light transmission rate of 99.35% between 400 and 700nm (visible spectrum). These coatings greatly reduce reflections off the surface of the glass allowing you tocapture more light in your photos. As with all HOYA multi-coatings, HD HMC is applied in a furnace at high he at, bonding the coating to the surface of the glass. This process is called "hard coating" and it is far more durable than other coating techniques. The chemistry of the top layer is formulated not just to be more durable but to be resistant to oil stains. This means that finger prints and other oils are much easier to remove