The Sigma 52mm 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    52mm 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.

52mm front filter threads allow for use with other filters.

Plastic filter case for storage and transport.

Related Questions and Answers

Q: 1. Will this fit on canon EF 50mm f/1.8 STM lens?

A: The Canon EF 50mm f/1.8 STM Lens accepts49mm filters, including this one.

Q: 2. What is the light transmission of this?

A: Sigma does not have any published specifications for light transmission of this CPL (which I believe is typical because most CPLs have filter factors in a range) but does advertise a 30% increased transmission over their competitors' CPLs. This filter does have a 0.3-0.5 stop reduction of light, which equates to a theoretical numerical transmission of 81.2% (at 0.3 stops) to 70.7% (at 0.5 stops), the formula being 100% multiplied by half to the power of 0.3 and 0.5.

Q: 3. 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: 4. 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.

Q: 5. hello! could this fit and work on the G Master 70 200mm? Thanks!

A: Yes, the Hoya 77mm NXT Circular Polarizer Filter will fit and work on the Sony FE 70-200mm f/2.8 GM OSS Lens.

Q: 6. 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: 7. WHAT OTHER BRAND 105mm CPL FILTERS CAN BE FITTED TO LEE 105mm CPL ADAPTER ONTO LEE 100mm FILTER HOLDER?

A: As long as you have this 105mm adapter on your Lee foundation kit: https://bhpho.to/2cujqJ5 You will be able to use any filter that has 105mm threads such as this Haida 105mm circular polarizer.

Q: 8. 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: 9. Does this filter fits in NiSi V6 filter holder?

A: Yes, the Haida NanoPro CPL Circular Polarizing Filter (100 x 100mm) would be compatible for use in the NiSi V6 100mm Filter Holder.

Q: 10. Is this filter adjustable depending on how much you want have polarized? I mean, is it like the filter you turn to left or right depending the adjust you want to have?

A: Yes, a circular polarizer will rotate depending on the degree of polarization that you want in an image.