The Hoya 52mm HD Hardened Glass 8-Layer Multi-Coated Digital UV Filter is a multi-purpose fine-weather filter that is designed to optimize the photography experience of the digital SLR user. UV filters which absorb ultraviolet rays that often make outdoor photographs hazy and indistinct should be constantly fitted to a lens to provide improved clarity and color balance as well as to provide protection to your lens. Hardened Optical Glass that has 4 times the breaking strength in ANSI standardized testing (ANSI Z80.3 : 2001) where steel balls of varying size and weight were dropped from a height of 50 inches onto the glass. Newly developed industry leading Hardened 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 to capture more light in your photos. As with all HOYA multi-coatings HD HMC is applied in a furnace at high heat 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. Key Features: HD Glass; High Density Sharp Cut UV Glass Chemically Enhanced Optical Glass is 4x Stronger HD Coating; 8-Layer Anti-Reflective Multi-Coating Water, Oil, Repellent, Scratch, Stain Resistant HD Frame; Wide-Angle Lens Compatible Ultra Thin Frame Glass Mounted with High Pressure Technology.