The Schneider 5.65" Circular Polarizer Filterfrom Schneider 5.65" 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 5.65 x 5.65" 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. 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: 2. What is the rear opening mm size of the matte box?

A: The largest size lens this matte box can work with is 134mm. It included 80, 90, 114 and 134mm lens adapters.

Q: 3. Is it threaded to hold a 40.5mm ND filter like the standard tray in the 400 2.8?

A: No, the Sony Drop-In Circular Polarizing Filter for Sony FE 400mm f/2.8 GM OSS Lens is strictly for polarization and cannot have the filter changed.

Q: 4. Will this filter fit the Sony (or Minolta) A-Mount 500mm F/8 reflex lens?

A: No, this Sony Drop-In Circular Polarizing Filter for Sony FE 400mm f/2.8 GM OSS Lens is not compatible with the Sony A 500mm f/8 Reflex Lens.

Q: 5. Does the B&H version of this matte box come with the 5 front sun shades pictured in some of the ebay listings?

A: Yes!

Q: 6. 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: 7. 2 stage r 3 stage matte box

A: The Tilta 4 x 5.65 Carbon Fiber Matte Box B&H # TIMBT04 is a two stage matte box.

Q: 8. Does this fit in the new 300mm f2.8 Sony lens?

A: Yes, the Sony Drop-In Circular Polarizing Filter for Sony FE 400mm f/2.8 GM OSS Lens is also compatible with the Sony FE 300mm f/2.8 GM OSS Lens (Sony E).

Q: 9. Does this come with a filter pouch?

A: Yes, an individual filter pouch is included in the box with Lindsey Optics 138mm Brilliant Rota-Pol Circular Polarizer for 4 x 5.65" Cine Matte Boxes.

Q: 10. how does this sit on 15mm rod system? is it fully adjustable back and forward with the adaptor?

A: I do not use the bottom flag mount, so I have removed it and the rods clear.