Circular Polarizing (CPL) Filter — Compatible With Sigma 50-200mm f/4-5.6 DC OS HSM K

Built with an ultra-slim aluminum frame to avoid vignetting while maintaining rotation capabilities for adjusting levels, this circular polarizer is engineered for wide compatibility and precise control. Nonslip upper rim helps install, rotate and remove easily. It features double sided, multi-layered coatings, anti-oil, anti-dust, anti-soil, scratch & water resistant for durable, long-lasting performance. As a Circular CPL filter, it reduces unwanted reflections from non-metallic surfaces such as water, glass, etc., and boosts overall color and contrast. Photographers commonly use it to increase contrast and saturation in blue skies and white clouds and to clear haze in distant landscapes for more saturated, vivid colors. CPL filters arrange and filter directionally polarized light perpendicularly to the reflected light, allowing for the absorption of much of the light. For maximum effect position the filter at a 90° angle from the sun.