The Irix 95mm Edge Circular 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.

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A circular polarizer only differs from a linear polarizer in that it contains a quarter wave plane in addition to the linear polarizing filter. The addition of this quarter wave plane is to circularly polarize the 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, 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 constructed from Schott glass for increased clarity and features an aluminum-alloy filter ring that can be rotated to adjust the intensity of the polarization effect. To prevent internal ghosting and reflections, each glass surface includes multiple layers of anti-reflection coating. An additional water-repellent and stain-resistant coating on each glass surface offers greater protection to the filter substrate and helps it to stay clean for longer than with uncoated filters.