The Sigma 46mm WR (Water Repellent) 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.

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 multi-coated to eliminate internal ghosting and reflections. An anti-static coating serves to limit the accumulation of static electricity, making dust particles easier to remove or preventing them from adhering to the filter. Additionally, a water-repellent coating results in an improved beading effect when in contact with water, as well as oil, for greater cleaning efficiency while enhancing scratch resistance.
Sigma WR Circular Polarizer filters are constructed from optical glass with a black rim. Set within an aluminum-alloy filter ring that can be rotated in order to adjust the intensity of the polarization effect, the glass provides increased clarity as well as color fidelity while the black rim further ensures that reflections do not occur along the filter's edge.

1.25 to 1.4x Filter Factor    +0.3 to 0.5 Stops    Helps to Eliminate Reflections and Glare    Reduces Haze in Landscapes    Greater Color and Tonal Saturation    Black-Rimmed Optical Glass, Multi-Coated    Water, Oil, Static, Scratch Resistant    Slim Aluminum-Alloy Filter Ring    46mm Front Filter Threads    Knurled Front Edge, Plastic Case

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.

Circular polarizers are ideal for use with digital cameras and autofocus lenses where a linear polarizer will often disrupt auto exposure and focus features.

Multi-coated to help eliminate internal ghosting and reflections.

Anti-static coating serves to limit the accumulation of static electricity, making dust particles easier to remove or preventing them from adhering to the filter.

Water repellent coating results in an improved beading effect when in contact with water, as well as oil, for greater cleaning efficiency while enhancing scratch resistance.

1.25 to 1.4x filter factor reduces exposure by 0.3 to 0.5 stops.

Constructed from clear, optical glass with a black rim which further ensures that reflections do not occur along the filter's edge.

Slim, aluminum-alloy filter ring helps to prevent vignetting and is durable while remaining lightweight.

Filter ring can be rotated to adjust the intensity of the polarization effect.

Knurled front edges provide a more textured grip when mounting or removing it from a lens.

46mm front filter threads allow for use with other filters.

Plastic filter case for storage and transport.

Related Questions and Answers

Q: 1. Will this work with the LEE Filters 105mm Accessory Front Thread Adapter Ring &H # LEFARPFK105?

A: yes, it will fit perfectly on the LEE Filters 105mm Accessory Front Thread Adapter Ring.

Q: 2. Will this work with a Lee Foundation Holder or a Cokin Z-Pro holder?

A: Unfortunately no, this filter will not work. Those filter systems require square or rectangular filters.

Q: 3. why am I having problems with scratches on the glasswhy am i getting scratches on the glass?

A: A filter like a lens is still glass and is sensitive to scratches like any other lens.Some filters are better than others. But a lens cap still needs to be used when using filter to protect it when you put it in a camera bag.

Q: 4. Any vignetting when mounted on a Zeiss 15mm lenses on Nikon D810?

A: This filter may cause vignette when mounted on a full frame camera and 15mm lens.

Q: 5. Can the included 46mm filter (glass only) in this Sigma Circular Polarizer Holder BH #SIAP2900 - MFR #AP2900 be replaced with another 46mm curcular glass polarizer?

A: No, the Sigma filter is specific to the holder.

Q: 6. Is this compatible with the NiSi 46mm Natural Night Filter?

A: Yes, the Sigma Filter Holder with WR Circular Polarizer RCP-11 Drop-In Filter would be compatible with the NiSi 46mm Natural Night Filter.

Q: 7. Real-life experience comparison regarding the 'water repellant' coating of this filter vs., say, the B + W circular pola? Any difference in environments with rain/snow/humidity? Thanks.

A: Yes, the water repellent works quite well when it comes cleaning the filter without leaving streaks,etc...,as well as not fogging up.

Q: 8. My Lumix LX100 is with the DMW-LFAC1 lens cap. Will this Hoya fix in well?Do you know it's thickness?I have a Cokin UV 3.3mm thickness lens and it slides/works perfectly.Looking forward to your kind reply. Thank you.

A: Yes, you could use this filter with the DMW-LFAC1 on the LX100.

Q: 9. Will this filter fit the 39 mm filter holder in my Nikon 300 mmm f/4 lens ?

A: Absolutely not

Q: 10. Is there any quality degradation on 150-600mm lens, at focal lenghts beyond 200mm?

A: The Sigma 95mm WR (Water Repellent) Circular Polarizer Filter would have the same effect on the lens at all focal lengths. While adding any optic in front of the optical formula of your lens will have some amount of effect to your lens' image quality, the Sigma 95mm WR (Water Repellent) Circular Polarizer Filter is a high-quality filter, and the benefit of its circular polarizing performance in reducing glare/flare from non-metallic items, increasing contrast/saturation, and deepening the blue hue in the sky (depending on your orientation to the sun) would mitigate any minor negative degradation you would obtain from using the filter on your lens.