The Tiffen 67mm Circular Polarizing Low-Profile Filter screws onto the front of lenses that have filter threads and are 67mm in diameter. It arranges and filters polarized light perpendicularly to the reflected light resulting in a reduction in glare and reflections and an increase in saturation in skies and foliage. The effect is strongest when used at a 90° angle from the sun. Unlike with linear polarizers, a circular polarizer won't disrupt AE and AF functions. This filter will reduce your overall exposure by 1-1.5 stops. The ultra-thin 4mm ring makes this filter suitable for wide angle lenses. It's used for water shots, wildlife, landscapes, and any other subject where you need to cut glare and add richness to greens and blues.