Nuances C-PL (Circular-Polarising) filters are ultra thin and lightweight filters, designed to remove unwanted reflections from non-metallic objects. They can be easily rotated to enhance colours and create stunning blue skies. With a thickness of just a few millimetres, they are almost invisible once screwed onto your lens, yet they still allow lens caps to be attached. They have been developed without compromise and are very robust, having been treated with Ever clear 5 surfacing technology to withstand the most extreme conditions. Ever clear 5 surfacing technology is a multi-layer coating and the "5" represents the benefits provided by this coating: water repellent, oleo phobic, anti-scratch, anti-dust and anti-stain. Their light-weight design allows maximum AF lens performance and the ultra-thin profile prevents vignetting. In sunny weather (especially in early morning or late afternoon) and if you maintain a right angle (90°) between the shooting axis and the position of the sun, a polarising filter will dramatically darken the blue of the sky, throwing white clouds into strong contrast. Polarising filters significantly improve the saturation of colours; you will obtain stronger greens, richer reds and ever more brilliant yellows. You will be surprised to see how certain colours, dull to the naked eye, become vibrant and dazzling with this filter. In all kinds of weather, polarising filters reduce, eliminate, and even deepen reflections on non-metallic surfaces such as water or windows. They bring transcendence to vegetation, transform bodies of water and open vistas. Note: With wide-angle lenses (24mm and shorter, in 35mm photography terms) the side of the image which is farthest from the sun will be darker than the other. This is an inevitable optical phenomenon, independent of the polarizing filter used. Nuances C-PL filters are made from tough Schott B270i high-resolution tempered glass, with excellent light transmission (only 1 stop light reduction) and they provide excellent protection against dust or scratches on your front lens element.