This Kase Filter Kit includes a UV filter and a circular polarizer filter. Each filter in this kit can provide one of two enhancements to your imagery while using a Canon EF 400mm f/2.8L IS USM Lens. A UV filter adapter ring is also provided, as well as a lens cap, and a filter case that can accommodate both filters, which feature multi-coated Schott B270 Superwhite glass for enhanced clarity and color fidelity.

A general-use, clear filter designed to absorb ultraviolet light and reduce the bluish cast of daylight, the UV Filter can be screwed on after the UV filter adapter ring is installed along the front of a compatible lens. Aside from the reduction of unwanted blue casts, no additional coloration or contrast is created while using this filter, and adjustments to exposure are not required. The UV filter is also useful as a general protective filter to leave on a Canon EF 400mm f/2.8L IS USM Lens at all times. Such filters help to reduce dust and moisture from reaching the front lens element and provide additional protection in case of situations where scratching could occur.

The circular polarizer 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 Canon EF 400mm f/2.8L IS USM Lens. 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.

The circular polarizer filter 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.

Screw-On UV Filter with Adapter Ring    Absorbs Ultraviolet Light    Reduces Bluish Cast of Daylight    1x Filter Factor, No Exposure Change    Drop-In Circular Polarizer Filter    2 Filter Factor, +1 Stop    Helps to Eliminate Reflections and Glare    Reduces Haze in Landscapes    Greater Color and Tonal Saturation    Lens Cap, Storage Pouch

• Absorbs UV light and reduces bluish cast of daylight
• Does not require adjustments to exposure while in use
• Creates no additional coloration or contrast
• General protection filter reduces dust, moisture, and scratches from reaching lens elements
• Schott B270 Superwhite glass for enhanced clarity and color fidelity
• Multi-coated to prevent internal ghosting and reflections

• 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
• 2x filter factor reduces exposure by 1 stop
• Schott B270 Superwhite glass for enhanced clarity and color fidelity
• Multi-coated to prevent internal ghosting and reflections

Related Questions and Answers

Q: 1. can the lens hood be Reinstalled in shooting position once this UV filter is attached?

A: The lens hood can't be reinstalled in shooting position once the Kase Filter Kit for Canon EF 800mm f/5.6L IS USM Lens is attached.

Q: 2. Does this lens have autofocus with the EF 2x III extender?

A: When using the 400mm f/4 with the 2X III Extender, you will retain autofocus with the 1D series and the 5D III with the newer firmware. With all other cameras, autofocus will be lost.

Q: 3. Does this lens with 1Dx II fit on E6 eagle series fotopro tripod with gimble head.?

A: Yes, but ideally for this lens setup and that camera you would want to go with the E9 Gimbal.

Q: 4. Will the autofocus work with this lens and the II or III extender on the Canon R?

A: The Canon EF 400mm f/4 DO IS USM Lens is not listed as compatible with the Canon Mount Adapter EF-EOS R and the II or III extender on the Canon R camera.

Q: 5. When dont I need to use the stabiliser

A: You will need a sitch image stabilization On in your Canon EF 400mm f/2.8L IS III USM Lens when you are hand-holding your camera and lens or using a monopod during panning with photos and videos.

Q: 6. Hi. Is this lens 100% compatible with 7d mark ii?

A: Yes this lens is 100% compatible with the 7d Mark II.

Q: 7. What is the wisest aperture at 400mm? Basically does this open up to f/2.8 at 400mm?

A: Yes. This is a prime lens (400mm only) and it opens up to f/2.8

Q: 8. can the lens hood be Reattached in shooting position once this UV filter is attached?

A: Yes, the lens hood can be reattached once you install the Kase UV filter on the lens.

Q: 9. Hi B&H,I recently purchased a 400DO II Lens from you. Now looking for a compact soft case to hold the lens and hood. Something like the Lowepro soft case, but unfortunately the Lowepro does not meet the required dimensions. Do you have another recommendation ? Your help is appreciated. Thanks Kent

A: I would recommend either the Kinesis E660 XX-Large Lens Pouch II, B&H # KIE660, the Lowepro Lens Case 13 x 32cm (Black), B&H # LOLC1332, the Ruggard Lens Case 12.0 x 5.0 (Black), B&H # RULCY112X5, or the OP/TECH USA Snoot Boot Wide Body (XXL), B&H # OPSBBXXLH, for your needs.

Q: 10. Anybody using this lens with 2X III? I'm wondering whether AF microadjustment is needed with this combo.

A: I have not used it for 2x.