hoya 72mm hd hardened glass 8-layer multi-coated digital circular polarizer filter
light rays which are reflected by any surface become polarised and polarising filters are used to select which light rays enter your camara lens . they allow you to remove unwanted reflections from non-metallic surfaces such as water glass etc. they also saturate colors and increase contrast . polarizers come in two variations but have the same effect . linear polarizers work with older camera meters circurlar polarizers are designed for today s newer split-beam metering systems used in auto focus cameras . check your camera s manual . 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 . high transparency polarizing film the polarizing film is the same as that used in the latest high definition lcd tv screens . it has 25 higher light transmission than standard polarizing film used in current photographic filters . hardened 8 layer waterproof multi-coating that is scratch amp 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 heat bonding the coating to the