The Schneider 4x4" Circular Polarizer Filterfrom Schneider 4x4" Circular Polarizer Filterhelps 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 non-coated and delivers approximately 38% average light transmission. Constructed from Water White optical glass, this 4 x 4" filter is unmounted for use in third-party or custom filter holders.

Unmounted Circular Polarizer Filter    For Third-Party or Custom Holders    2x Filter Factor, +1 Stop    Helps to Eliminate Reflections and Glare    Reduces Haze in Landscapes    Greater Color and Tonal Saturation    Non-Coated    Water White Optical Glass    Filter Pouch

Helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface.

Unmounted for use in third-party or custom filter holders for film and television cameras.

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.

Constructed from Water White optical glass.

Non-coated.

Approximately 38% average light transmission.

2x filter factor reduces exposure by 1 stop.

Filter Pouch for storage and transport.

Related Questions and Answers

Q: 1. How many stops of light do we lose by using this polarizer?

A: I contacted Sony concerning your inquiry. While they did not have an exact light loss listed for this Sony Drop-In Circular Polarizing Filter for Sony FE 400mm f/2.8 GM OSS Lens, they did state that circular polarizers typically block out half of light coming in, so typically light loss is 1-2 stops.

Q: 2. Can the actual circular filter be removed and replaced with another filter ?

A: No, the filter in the Sony Drop-In Circular Polarizing Filter for Sony FE 400mm f/2.8 GM OSS Lens cannot be removed and replaced.

Q: 3. Can you stack this circular polarizer on top of the Helix 2-5 VND filter?

A: The PolarPro Helix MagLock Burkard Edition Circular Polarizer Filter can be stacked on top of the PolarPro Helix Variable Neutral Density Filter (2 to 5 Stops).

Q: 4. Hi just wondering if when using this filter on a 4.5mm wide angle B4 ENG lens, weather you get any vignetting when fully wide as wanting to put in in the front tray of my Croszniel matte box not the rotating back one. Based on filter being 4 x 5.65 sizing as mentioned above?

A: The diameter of the filter is 4.5. If this is a larger diameter than the front element of the lens you own, you should be good.

Q: 5. There is no variable nd filter that works the same way for this lens ?

A: Unfortunately, there are no variable ND filters that drop in for the Sony FE 400mm f/2.8 GM OSS Lens.

Q: 6. Can this filter be used with Nikkor 180-400mm f/4?

A: Yes, this can be used with the AF-S NIKKOR 180-400mm f/4E TC1.4 FL ED VR lens.

Q: 7. Will the Nikon 2221 slip in filter work with the 400mm S lens?

A: No, the Nikon 40.5mm Drop-in Circular Polarizing Filter MFR 2221 ( https://bhpho.to/3J8jCvk ) is not compatible with the NIKKOR Z 400mm f/2.8 TC VR S lens. The Nikon C-PL460 Slip-In Circular Polarizer is compatible with the 400m S lens.

Q: 8. Does the circular polarizer for the FE400 also fit the FE600?

A: Yes, this filter and its holder will work in the FE 600mm and all Sony telephotos with drop-in filters.

Q: 9. Do you have 5 stop and a 10 stop ND filters that will screw in to these drop in filter holders?

A: The Nikon AF-S NIKKOR 400mm f/2.8E FL ED VR lens came with a drop in filter holder and a clear filter. You can remove the clear filter from your original holder and use any 40,5mm filter in the holder instead such as this 5 stop ND: https://bhpho.to/4al5eNO

Q: 10. Will this work with the Wooden Camera Zip Box Pro 4.5" Round Filter Stage?

A: Yes, the Lindsey Optics 4.5" Round Brilliant-Pol Linear Polarizer would work with the Wooden 4.5" round filter stage when using the Wooden Zip Box Pro. Wooden Camera Zip Box Pro 4.5" Round Filter Stage BH #WO271400