The Ultra-Pro Circular Polarising filter reduces unwanted reflections in non-metallic surfaces such as water and glass. It helps to boost contrast and colour saturation by filtering out light which has become polarised by reflection. This also helps increase contrast between blue sky and cloud as well as plant foliage. The circular polarisation is created by the addition of a quarter-wave film to the standard polarising film and this makes it ideal for use with all cameras, especially those with autofocus and complex exposure measurement systems. The Ultra-Pro Circular Polarising filter has 16 layers of anti-reflection, water and oil repellent coatings which, coupled with the high-grade polarising film provides a superb 90% light transmission.