Sigma 95mm Weather Resistant WR Circular Polarizer Filter: The circular polarizing filter is specifically designed for use with most of the auto focus SLR cameras and lens. The Sigma filter is an essential accessory for outdoor photography and fits to selected lenses with a 95mm filter thread. The filter removes unwanted reflections from non-metallic surfaces such as water or glass and also saturate colors providing better contrast. The polarizer helps make a blue sky more bluer as well as making clouds stand out. The effect can be seen through the viewfinder and changed by rotating the filter. Produce strongest effect when used at a 90° angle from the sun. The filter increases light transmission and colour saturation without affecting the overall colour balance. Clears up haze in distant landscapes and provides more saturated & vivid colours. The filter protect front lens surface from dust, scratches, dirt and fingerprints. The filter is lightweight and very easy to install & detach from lens.