Dollar for dollar, there is no other accessory that can make as noticeable an improvement in the way your outdoor photographs look as a Polarizing Filter offers you. Light rays which are reflected by any surface become polarized and Polarizing Filters are used to select which light rays enter your camera lens rather than allowing all the scattered multi-directional light waves to enter simultaneously which degrades picture quality. Both the older style PL (Linear Polarizing) and the more modern PL-CIR (Circular Polarizing) filters provide the same photgraphic effect, but it is important to use the correct version for your camera. Many of today"s cameras use semi-silvered mirrors or prisms to split the light entering the viewfinder in order to calculate exposure and focusing distance. Older style PL (Linear Polarizing) filters can sometimes interact with these items to give unpredictable exposure or focusing. So it is recommended that you choose a PL-CIR (Circular Polarizing) filter which will work on both the most modern digital cameras as well as the older manual focus film cameras. They allow you to remove unwanted reflections from non-metallic surfaces such as water, wood, grass, leaves, snow, glass, etc. They also enable colors to become more saturated and appear clearer, with better contrast. This effect is often used to increase the contrast and saturation in blue skies and white clouds for incredibly vivid yet natural looking scenic photographs. In addition, HOYA"s Polarizing Filters do not adversely affect the overall color balance of the photograph. Hoya Multi-coated HMC filters are renowned for their ability to minimize reflection at the filter surfaces which reduces flare and ghosting to enhance the performance of today"s multi-cpated lenses. The result is an average light transmission of over 97%, giving sharp contrast and well balanced color.