The HD Nano Circular Polarizing filter is sharper and 200% harder than the award-winning HD circular polarizer filter. In addition to being scratch and abrasion resistant, this hardened coating is also stain resistant and easy to clean when oil and smudges like fingerprints are introduced to the surface. Hoya selected a premium optical-thin high rate transmission (HRT) polarizing film that passes 2/3rds of a stop more light through the filter for faster, more accurate AF and easier viewing through the viewfinder or LCD screen. Re-Certified Resolution for 100mp+ Cameras Patented Ultra-hard Nano-coating process Superior resolution and sharpness Optical thin HRT Polarizing Film Only 1-stop of light loss Waterproof and stain-resistant top coat