Osaka 58mm CPL Circular Polarizer Filter Circular Polarizer Filter helps you to remove unwanted reflections from non-metallic surfaces such as water, glass. They also enable colours to become more saturated and appear clearer, with better contrast. The effect is often used to increase the contrast and saturation in blue skies and white clouds. The effect can be seen through the viewfinder and changed by rotating the filter. "Osaka" and "Sonia" from the "Sonia Photo World" otherwise poor products or any other non-recommended or non-compatible fitments with our products are not eligible for warranty.