Hoya HD Filters are the new PREMIUM quality filters that are the benchmark for the photography industry.
They have 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. This means its HIGHLY SCRATCH RESISTANT. It is also water, stain resistant and FINGER PRINT RESISTANT!
This means that, not only will it take the pressure of what you throw at your lens – but it will take what mother nature throws at it as well! These scratch resistant, water resistant, fingerprint resistant and stain resistant filters are the best investment to put in front of your lens.
These HD filter have a factor of 1 1/6th stop Loss of light.