M10 Drop-in Nano-coating CPL + ND0.9 Filter

This Drop-In Neutral Density and Circular Polarizer Filter combines a solid neutral density effect with a circular polarizer effect. It is mounted within a drop-in assembly that is made specifically to fit between a separately available M10 Filter Holder and an adapter ring for the filter holder. The geared filter ring assembly’s external dial allows for the independent rotation of the circular polarizer filter to adjust the intensity of its effect.

Its density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required. By slowing your exposure time or increasing your aperture, you can control the depth-of-field and convey movement more easily. Simultaneously, this filter can help 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 autofocus and exposure functions. Due to how the light is broken down and filtered with a linear polarizer, autofocus 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 color fidelity. To prevent internal ghosting and reflections, each glass surface includes 10 layers of anti-reflection coatings, which also offer greater protection to the filter substrate and help keep it clean for a longer period of time. The Nano coating associated with this Drop-In Neutral Density Filter provides an additional layer that results in an improved beading effect when the surface comes in contact with water or oil, allowing for more efficient cleaning.