Helping to reduce reflections and glare, the 49mm Linear Polarizer Filter from Hoya filters out light that has become polarized due to reflection from a non-metallic surface. By filtering this light, a noticeable increase in the saturation of skies and foliage is possible, as well as the ability to produce clearer imagery when photographing in hazy conditions. The filter is constructed from optical glass and is mounted within a durable, lightweight aluminum ring that has a hard anodized finish to guard against wear.
A linear polarizer differs from a circular polarizer in that it does not support the use of a camera's autofocus or auto exposure functions; it is best suited for use with manual cameras, such as view cameras, that are not dependent on internal mechanisms to determine focus or metering settings.