Schneider 138mm Unmounted ND and Circular Polariser Filter (4-Stop)

Description

The Schneider 138mm Unmounted ND and Circular Polariser Filter is a filter that combines a solid neutral density effect with a circular polariser effect. When in use, this filter's 16x filter factor provides a 4-stop exposure reduction. Its 1.2 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 are able to control 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 polarised due to reflection from a non-metallic surface. The light from the sun naturally becomes partially polarised due to reflecting off electrons in air molecules, causing the light to scatter into what appears as haze. A polarising filter arranges and filters this directionally polarised 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 polariser only differs from a linear polariser in that it contains a quarter wave plane in addition to the linear polarising filter. The addition of this quarter wave plane is to circularly polarise the linearly polarised light for the use of auto focus and exposure functions. Due to how the light is broken down and filtered with a linear polariser, auto focus and exposure accuracy become skewed during use. When the light becomes circularly polarised, it permits the use of these functions.

This filter is constructed from Water White optical glass, and it is 138mm in diameter and unmounted for use in third-party or custom filter holders.

Key Features:

• Unmounted for use in third-party or custom filter holders for film and television cameras.
• 1.2 neutral density filter effect darkens the image, allowing you to photograph with a longer shutter speed or wider aperture than normally required.
• Providing a 16x filter factor with a 4-stop exposure reduction, this filter allows you to control depth of field and convey movement more easily.
• Polarising filter effect arranges and filters directionally polarised light perpendicularly to the reflected light, allowing for the absorption of much of the light.
• Helps to reduce reflections and glare by filtering out light that has become polarised due to reflection from a non-metallic surface.
• Clears up haze in distant landscapes and provides more saturated, vivid colours.
• Strongest polarisation effect when used at a 90° angle from the sun.
• Circular polariser effect is ideal for use with digital cameras and autofocus lenses where a linear polariser will often disrupt auto exposure and focus features.
• Constructed from Water White optical glass.
• Filter pouch for storage and transport.