The Kenko Circular Polarising filter is used to increase colour saturation, darken skies so white clouds stand out, and eliminate reflections from non-metallic surfaces like glass or water. It will also reduce the softness in scenery caused by atmospheric haze. Circular polarisers are designed to be used with the metering systems of modern SLR and digital cameras and will not change the overall colour balance of a photograph. Filter Factor 3~4 (1 2/3 to 2 stops) CPL filters are invariably thick because they consist of two pieces of glass. However, thin-frame types are also available, in which the glass assembly has been ground to a thickness equivalent to that of a normal filter. CPL filters achieve their greatest effect of eliminating glare when used at a 30-40 degree angle to a reflective surface (like glass or water). At midday when the sun is directly overhead, or at a 90 degree angle, the filter will have the least effect. These effects are easily visible by rotating the filter and looking through the viewfinder of the camera. Keep in mind that you will first need to adjust the polarizing filter before setting the exposure controls. For deepening the color of the blue sky and making the clouds jump out at you, hold the camera at a right angle to the sun and take the photo when the sun is at a 30-40 degree angle in the sky. When photographing distant subjects, scenery sometimes appears bluish. This is also caused by light polarization. Using the polarizing filter will help to greatly reduce the softness caused by atmospheric haze. There are a variety of ways in which the use of polarizing filters can help you capture that perfect shot. Reducing the haze and enhancing colors may seem like simple effects, but once used, these effects will prove to be invaluable to photographers at any level of interest.