The Veydra 4 x 5.65" Linear Polarizer Filter helps to reduce 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 polarizing filter 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.A linear polarizer differs from a circular polarizer in that it does not contain an additional quarter wave plane. The addition of a quarter wave plane is to circularly polarize linearly polarized light for the use of auto focus and exposure functions. Due to how the light is broken down and filtered with a linear polarizer, in-camera auto focus and exposure accuracy become skewed during use. When the light becomes circularly polarized, it permits the use of these functions.This filter is recommended when not using in-camera exposure metering or autofocus. To prevent internal ghosting and reflections, each glass surface includes 16 layers of anti-reflection coating. These coatings also offer greater protection to the filter substrate and help it to stay clean for longer than with uncoated filters. This filter is constructed from Schott glass for increased optical clarity as well as color fidelity. It can be used along with a Veydra 138mm Unmounted Circular Polarizer Filter that is installed within a Veydra 4 x 5.65 / 138mm Revar Cine Rota-Tray. Both the Veydra 4 x 5.65 Linear Polarizer Filter and a Veydra 138mm Unmounted Circular Polarizer Filter can then work together inside of a top-loading, two-tray matte box to provide the effect of a solid variable neutral density filter that features an exposure reduction of approximately 2 to 8 stops.Helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface.Polarizing filters arrange, and filter, directionally polarized light perpendicularly to the reflected light, allowing for the absorption of much of the light.Clears up haze in distant landscapes and provides more saturated, vivid colors.Strongest effect when used at a 90? angle from the sun.Recommended when not using in-camera exposure metering or autofocus.Multicoated with 16 layers of anti-reflection coating on each glass surface.4x filter factor reduces exposure by 2 stops.Constructed from Schott glass for optical clarity.Nylon pouch included for storage and transport.Inside of a top-loading, two-tray matte box, can be used along with a Veydra 138mm Unmounted Circular Polarizer Filter that is installed within a Veydra 4 x 5.65 / 138mm Revar Cine Rota-Tray to provide the effect of a solid variable neutral density filter that features an exposure reduction of approximately 2 to 8 stops.