The FotodioX 145mm Circular Polarizer Filter is compatible with the FotodioX WonderPana 145, FreeArc, and Absolute filter holder systems. It helps to reduce reflections as well as 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.

The FotodioX 145mm Circular Polarizer Filter is constructed from optical glass for clarity as well as color fidelity and features lightweight, aluminum-alloy filter rings. A rear filter ring connects to a compatible filter holder while four brass knobs along the side of the front filter ring allow the filter glass to be easily rotated. This provides the ability to achieve the desired degree of polarization even if another filter is placed in front of the FotodioX 145mm Circular Polarizer Filter.

For Sigma 12-24mm f/4.5-5.6 DG HSM II    WonderPana 145 Core Unit    145mm Circular Polarizer Filter    1.25 to 8x Filter Factor, +0.3 to 3 Stop    Helps to Eliminate Reflections and Glare    145mm Center-Pinch Snap-On Lens Cap

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.

1.25 to 8x filter factor reduces exposure by 0.3 to 3 stops.

Constructed from optical glass for clarity.

Lightweight, aluminum-alloy filter rings along with four brass side knobs allow the filter glass to be easily rotated. The desired effect can be easily achieved even if another filter is placed directly in front.

Filter pouch included for storage and transport.

Related Questions and Answers

Q: 1. How does this fit the Sigma 12-24mm when the hood doesn't detach? Do I need another accessory?

A: Nothing additional is needed. This fits over the hood. There are a few filter holders on this page. For the Sigma 12-24mm Art Lens make sure to select the holder that is specifically for that lens. BH #FO186EKS1224 • MFR #WNDPN186-ESNTLCP-SM1224F4

Q: 2. 1. Can this circ-polarizer be stacked with a wonder-pana solid ND filter? e.g. using both polariser and ND-8 filter (or ND-32 filter) together? 2. If they can be stacked, will vignetting be observed on the Nikon 14-24 with two circular filters stacked? 3. Can we stack a circular wonderpana 145 filter with their rectangular 66 graduated ND filters? 4. If we can stack a circular with rectangular GND, will vignetting be observed on the Nikon 14-24 with total 2 filters (1 circular and 1 rectangular)?Thank you!

A: WonderPana 145/66 system allows stacking of one round filter like the polarizer and one rectangle filter or two rectangle filters. With the adapter for the Nikon 14-24 lens you can use this set up on that lens.It is designed not to vignette.

Q: 3. Can I use a 77mn variable nd filter with this adaptor? I have tokina 16-18 mm

A: FotodioX WonderPana 145 Core Unit Kit for Tokina 16-28mm Lens is very wide. It accepts 145mm filters. Unfortunately 77mm filters won't work as they are too small.

Q: 4. Will this also fit the new f2.8 version of the 12-24?

A: No, this is for the f/4 version of the Sony 12-24mm zoom lens only.

Q: 5. Where would the CPL be located when stacked? Front or back of the circular ND filter? thanks.

A: Most likely I would stack on the outside not the back in order to adjust polarizer

Q: 6. How do you adjust the polarized lens to avoid the line through your picture? Without downloading pictures onto computer

A: Hi Jeff, you mean the black shade in a picture, if I take this between 12-16mm wide angle, right? It depends to the angle of the sunlight and in which angle I take that image. Usually it is not possible to adjust it in advance if you need to take that pic with 12mm wide angle.Bad luck...Best regards Vedat

Q: 7. Hi,if i need nd filter for panasonic lens 7-14mm,what i need also do you have any variable nd filter?

A: I'm not aware of a variable ND option for this product. However, in my experience variable ND filters are very challenging to use with ultra wide angle lenses. I find fixed ND filters a much better option.

Q: 8. Do I need to buy another lens ring to fix this filter? This adapter is immediately attached to the lens or you need to buy something else? What is included with this filter?

A: What you see is in the photos is all you need if you want to use the polarizer. In the Box: FotodioX 186mm Slim Circular Polarizer Filter Filter Pouch Limited 2-Year Warranty FotodioX 186mm Center-Pinch Snap-On Lens Cap for Select WonderPana Systems & Filters Limited 2-Year Warranty WonderPana FreeArc XL Core Unit for Sigma 14-24mm f/2.8 DG HSM Art Lens Limited 2-Year Warranty If you want to use the square or rectangular filters, then you will need the brackets. Click on the link below to view; https://bhpho.to/32VgMWY

Q: 9. I need to use a clear or haze filter. Is it possible to utilize more than one filter at a time-a polarizer and an ND filter?

A: You cannot stack a uv filter on top of the Slim Circular Polarizer Filter included with the FotodioX WonderPana FreeArc XL Core Unit Kit for Sigma 14-24mm Art Lens with 186mm Slim Circular Polarizer Filter. Fotodiox 186mm filters are not designed with a front threads.

Q: 10. Will this work on the new Sigma 12-24 Art?

A: It works well with the 11-24 canon so I can only assume that it will work with that lens. n Needs to be kept spotlessly clean so as to avoid flare abboration