The Hoya 67mm HD3 Circular Polarizer Filterhelps 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.

While providing over 92% light transmission, 8 layers of anti-reflection nano coatings on each side, for a total of 16 layers, are applied to the Hoya 67mm HD3 Circular Polarizer Filter. These coatings offer a high degree of protection to the filter substrate and help it to stay clean for longer than uncoated filters. The nano coating formula associated with HD3 Circular Polarizer filters results in an improved beading effect when in contact with water for greater cleaning efficiency and is also effective with regard to oil and stains while also helping to prevent scratches.

Circular Polarizer Filter    2x Filter Factor, 1.0 Stop    Helps to Eliminate Reflections and Glare    Reduces Haze in Landscapes    Greater Color and Tonal Saturation    16-Layer Nano Multicoating    Optical Glass    Thin, Aluminum-Alloy Filter Ring    67mm Front Filter Threads    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.

8-layer nano multicoated on each side, for a total of 16 layers, for increased light transmission compared to uncoated glass.

Resistance coating provides an improved beading effect with water, oil, for more easier cleaning smudges and stains. The hard coating is durable enough to help prevent scuffs and scratches.

Approximately 92% average light transmission.

Constructed from optical glass for clarity and color fidelity.

2x filter factor reduces exposure by 1.0 stops.

Thin and durable aluminum-alloy filter ring minimizes the potential for vignetting when used with wide-angle lenses.

Plastic filter case for storage and transport.

Related Questions and Answers

Q: 1. 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: 2. what storage/carrying pouch would you advise for this item, when it is not fitted to the lens?

A: The Sony Drop-In Circular Polarizing Filter for Sony FE 400mm f/2.8 GM OSS Lens can be stored a in filter pouch, like the Ruggard 4-Pocket Filter Pouch (Up to 86mm), B&H # RUFPB244B.

Q: 3. does this filter come with any type of storage case?

A: Yes, this filter does include a storage case.

Q: 4. 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: 5. Will this work with the Tilta 3-Stage 4 x 5.65" Carbon Fiber Clip-On Matte Box?

A: Yes this can fit in that Tilta matte box. The matte box can hold thee 4 x 5.65 filter trays.

Q: 6. Will this rota-polo fit into the Wooden Camera 2 stage clamp on universal matte box? (SKU 201900)

A: Yes, the Lindsey Optics 138mm Brilliant Rota-Pol Circular Polarizer for 4 x 5.65" Cine Matte Boxes is compatible with the Wooden Camera UMB-1 Universal Matte Box (Clamp On).

Q: 7. Is it compatible with Sony E mount lens 100-400mm

A: No, the 100-400mm does not use a rear drop in filter.

Q: 8. 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: 9. Does this filter work with Kowa LM16HC lens? I think the filter thread fir t that is M35.5x0.5

A: No this filter will not work on this lens. The lens has a 35.3x0.25 mm thread this filter is too small.

Q: 10. 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.