Hoya HRT 77mm Circular Polarizing filter is designed to block ultraviolet light and reduce the bluish cast of daylight while also helping to eliminate reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface.
The light from the sun naturally becomes partially polarized due to reflecting off electrons in air molecules, causing the light to scatter into what appears as haze. A filter with polarizing capability arranges, and filters, this directionally polarized light perpendicularly to the reflected light, allowing for the absorption of much of this light. This results in a noticeable reduction of glare and reflections from non-metallic surfaces and an increase in the saturation of skies and foliage. This circular polarizer is ideal for use with digital cameras and autofocus lenses where a linear polarizer will often disrupt auto exposure and focus features. Hoy manufactures full range of HRT filters.
Features - Hoya HRT 77MM Circular Polarizing + UV Filter
An essential accessory for outdoor photography
Lightweight and very easy to install & detach from lens
Slow down shutter speeds in daylight to render moving subjects invisible
Reduce reflection at the filter surfaces which eliminate flare and ghosting
Protect front lens element from scratches, dirt build up, moisture and other damages
Also can reduce or eliminate reflections from non-metallic surfaces such as glass and water
Transmits as much as 25% more light through the polarizing film giving the photographer about 1/3 stop more light than a standard circular polarizer
The effect can be change by simply rotating the outer ring of the filter and can be seen by looking though the filter or through the viewfinder if it is mounted on a camera.