The Tiffen 138mm Self-Rotating UltraPol Circular Polarizer Filter is a mounted filter that includes rear and front threads that allow filter stacking when using third-party or custom filter holders. This filter's rear threads are intended to retain a 138mm non-self rotating mounted filter that is already placed within a compatible filter holder. A supplemental effect is then provided in addition to that of the retained filter. The Tiffen 138mm Self-Rotating UltraPol Circular Polarizer Filter's front threads can then accommodate an additional non-self rotating mounted filter, which can then be held in place with a 138mm retaining ring. Alternatively, another Tiffen 138mm self-rotating filter may be screwed on top of the Tiffen 138mm Self-Rotating UltraPol Circular Polarizer Filter.

Once installed, this filter helps 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.

This filter is non-coated, has approximately 40% average light transmission, and is designed to provide a polarization effect that is 15 to 20% greater than other Tiffen filters which only provide a linear or circular polarization effect and are not UltraPol filters.

The Tiffen 138mm Self-Rotating UltraPol Circular Polarizer Filter is constructed from Water White glass for increased clarity as well as color fidelity.

Mounted Circular Polarizer Filter    Allows Stacking with Filter Holders    Enhanced Polarization Effect    4x Filter Factor, +2 Stops    Helps to Eliminate Reflections and Glare    Reduces Haze in Landscapes    Greater Color and Tonal Saturation    Non-Coated    Water White Glass Construction    Padded Pouch

Mounted with front or rear threads that allow filter stacking when using third-party or custom filter holders for film and television cameras.

Rear threads retain a 138mm non-self rotating mounted filter that is already placed within a filter holder.

Front threads can accommodate an additional non-self rotating mounted filter witch can then be held in place with a 138mm retaining ring.

Front threads allow stacking with another Tiffen 138mm self-rotating filter.

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.

Offers a 15 to 20% greater polarization effect than other Tiffen filters which only provide a linear or circular polarization effect and are not UltraPol filters.

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.

Non-coated.

Approximately 40% average light transmission.

4x filter factor reduces exposure by 2 stops.

Constructed from Water White glass for increased optical clarity.

Aluminum-alloy filter ring for durability while remaining lightweight.

Filter ring can be rotated to adjust the intensity of the polarization effect.

Padded pouch included for storage and transport.

Related Questions and Answers

Q: 1. Would this work with a Canon 5DMII and battery grip and easily switch to vertical-portrait position without hitting the side of the handle?

A: There is 9in from the bottom bar to the top bar, so if your camera with batter is less than 9in is should work for you, I hope that helps

Q: 2. Three set screws underneath the collar enable you to fasten the head securely to the plate.What exactly does this refer to? How does this relate to Oben heads for example which do not show an ability to be screwed to the plate other than with the main reversible mounting screw?

A: All of the ball heads will screw onto the tripod center column plate and are snugged down by hand. On some tripods, under the center column plate are three set screws that when run in from underneath will contact the underside of the ball head. This helps keep the ball head from unscrewing when panning back and forth over time. Hope this helps, Kirk

Q: 3. Hi,I'm thinking of buying the OBEN ACM-2400L along with 'Manfrotto 498RC2 Midi Ball Head with 200PL-14 QR Plate'. Are they compatible to one another? Manfrotto monopod with self-standing legs is a bit too long for my liking (31' with ball head)

A: Yes. The 498RC2 Ball Head will work on the Oben ACM-2400L. Since the monopod has both a 1/4-20 and 3/8 compatible male thread, any standard head will work.

Q: 4. Do you need a ball head?

A: You only really need a single axis head such as the Oben VH-R2. With a monopod you pan by simply rotating the entire monopod. Such a head is easier to adjust one-handed when using a monopod. Unlike a tripod, a monopod won't stand on its own while you use one hand to hold the camera/lens so they don't flop around while using the other hand to loosen and tighten the adjustment knob.

Q: 5. Is this compatible with A7R4 and the Tamron 35-150 f2.-2.8?

A: Yes, this would be compatible with the Sony A7R IV and the Tamron 35-150mm F2-2.8 since the NiSi Silence Corner Atoll S connects to the camera itself and not the lens for quick lens changing and easy camera rotation.

Q: 6. is it compatible with sony a7C?

A: Silence Corner Atoll S Rotating Camera Collar for Select Sony Mirrorless Cameras will work with the Sony a7C Mirrorless Camera. Check the compatible lens options here: https://bit.ly/3nmCqSp.

Q: 7. Will this work with the a7iii and 24GM 1.4 lens?

A: Yes, as well the other following bodies mentioned Sony: FX3, a7C, a1, a9, A9 II, a7, a7 II, a7 III, a7 IV, a7R, a7R II, a7R III, a7R IV, a7R V, a7S, a7S II, a7S III

Q: 8. Is this rail useful for making macro/close-up videos? Will the footage be smooth? Thank you

A: Yes the Leofoto MP-180S Macro Focusing Rail with Rotating Arca-Type QR System (7.1") is useful for macro video and photos. The smoothness of the footage would depend on many different factors.

Q: 9. Is it possible to remove the legs from the bottom cap, or purchase a bottom cap without the legs?

A: The legs are stored inside the monopod and that acts as the cap for the bottom when you are not using the legs. It is best described on page 7 of the user manual: https://bhpho.to/2waKRWW

Q: 10. What additional attachment is required for a manfrotto tripod?

A: No additional accessories are required to use this--the Silence Corner Atoll S for Sony Mirrorless Cameras has a 1/4" mounting thread on the bottom for mounting it to a tripod head and a 1/4" mounting screw for attaching the camera.