This Sony Drop-In Circular Polarizing Filter helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface. It is made specifically to fit within the accessory filter slot of the Sony FE 400mm f/2.8 GM OSS Lens, whose front diameter is too large to accommodate a screw-on filter. With that lens, the effect of this filter occurs behind the main glass elements instead of in front of them.

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 constructed from optical glass for clarity and includes an integrated locking mechanism to secure it within the compatible lens, as well as an external dial to allow rotation of the filter glass for control of the polarization effect.

Drop-In Circular Polarizer Filter    Fits Sony FE 400mm f/2.8 GM OSS Lens    Helps to Eliminate Reflections and Glare    Reduces Haze in Landscapes    Greater Color and Tonal Saturation    Optical Glass Construction    Plastic Case

Compatible with Sony FE 400mm f/2.8 GM OSS Lens

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 perpendicular 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 optical glass for clarity

Plastic filter case for storage and transport

Related Questions and Answers

Q: 1. Does this lens have internal zoom and focusing or does it "grow" in length zooming from 100 to400?

A: the lens expands as you zoom in.

Q: 2. If this lens is used with the 1.4X and 2X telextenders will it autofocus on the A7rII?

A: Autofocus will be available on this lens when an FE 1.4X or 2.0x Teleconverter is attached while using it with the A7R II.

Q: 3. Is there a specific Arca-Swiss QR plate that is best for this lens?

A: This Wimberley P20 Quick Release Plate is a great arca type plate to use with the Sony FE 100-400mm f/4.5-5.6 GM OSS Lens. https://www.bhphotovideo.com/c/product/205334-REG/Wimberley_P_20_P20_Quick_Release_Plate.html

Q: 4. Will the Sony FE 1.4x Teleconverter B&H # SOTC14 MFR # SEL14TC work with this lens?

A: I am not sure that adding a tele conver is worth it.The Sony 100-400 is the greatest lens I have ever seen. It is so clear it's out of world.Eric G

Q: 5. Is it compatible with the RRS quick lever release clamp?

A: Yes, it will work for the RRS clamp.

Q: 6. Would this work with the first Sony A7 ? and what would I lose in quality and features?

A: Yes, it's fully compatible with the Sony A7 and no loss in quality or features.

Q: 7. I shoot most images from a tripod, and very often images wherein I am angling the camera downward (including some straight down) - since the focal length cannot be locked, does the lens' Tight/Smooth feature work well enough to keep the lens from creeping while taking long shots?

A: The Sony FE 100-400mm f/4.5-5.6 GM OSS Lens has a zoom torque adjustment that allows you to tighten the zoom ring so that lens creep is not a problem.

Q: 8. How does it feel in your hand? Does it provide grip support for hand holding?

A: Based on the feedback we received on this product, it is comfortable to hold while adding grip support to these Sony lenses.

Q: 9. Does sony make an adapter so I can mount this to my iPhone?

A: Good one (not).

Q: 10. I used this lens and a7R3 to photograph trumpet swans in RAW. The images of trumpet swans do not look sharp at 100% zoom or Actual Pixels View on the Sony Viewer software, do you experience the same effect? Thank you.

A: There could be several reasons the images aren't as sharp as you expected, some pertaining to the lens itself. I'd recommend reaching out to us over our new video-chat feature (bottom right of our B&H webpage) and we can discuss the issue! :)