The Hoya 49mm Circular Polarizer Slim 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 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 optical glass for clarity as well as color fidelity and features a thin, aluminum-alloy filter ring that can be rotated to adjust the intensity of the polarization effect. To prevent internal ghosting and reflections, eight layers of anti-reflection multi-coatings are applied to the filter's glass. These coatings also offer greater protection to the filter substrate and help it to stay clean for longer than with uncoated filters.
- Helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface.
- Arranges, and filters, 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.
- Ideal for use with digital cameras and auto focus lenses where a linear polarizer will often disrupt auto exposure and focus features.
- 2x filter factor reduces exposure by 1 stop.
- Constructed from optical glass for clarity and color fidelity.
- Eight layers of anti-reflective multi-coating help prevent internal ghosting and reflections.
- Thin and durable aluminum-alloy filter ring minimizes the potential for vignetting when used with wide-angle lenses.
- Filter ring can be rotated to adjust the intensity of the polarization effect.
- Plastic filter case for storage and transport.
