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This Genustech 77mm Variable Neutral Density and Circular Polarizer Filter is a filter that combines a solid variable neutral density element with a circular polarizer element. The variable neutral density element provides an exposure reduction of 2 to 8 stops. Its 0.6 to 2.4 density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than would normally be required. The degree of density is easily controlled by rotating the front filter ring, helping you to predetermine the additional exposure length required. By slowing your exposure time or increasing your aperture, you are able to control depth of field and convey movement more easily.
Behind this filter’s variable neutral density element is an independently-rotating circular polarizer element that can be applied 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 element 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.
The Genustech 77mm Variable Neutral Density and Circular Polarizer Filter is constructed from Water White glass for increased clarity as well as color fidelity. Each side of this filter includes a layer of anti-reflection coating to prevent internal ghosting and reflections. It also features an oversized front mount which helps to reduce the likelihood to vignetting when used with wide-angle lenses. The filter rings are made from aluminum alloy for durability while remaining lightweight, and for easier, repeatable control over density settings, the front ring for the variable neutral density element is visually demarcated with index markers that indicate different density values.
Variable neutral density filter element that allows differing amounts of density from scene to scene combined with a circular polarizing element that can be applied to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface
0.6 to 2.4 variable neutral density filter element darkens the image, allowing you to photograph with a longer shutter speed or wider aperture than normally required
Providing a reduction of 2 to 8 stops, variable neutral density filter element allows you to control depth of field and convey movement more easily
Offers increased flexibility to use specific ISO settings or ISO films under bright ambient light
Provides increased exposure flexibility while using cinema or video cameras within a designated film frame rate
Polarizing filter element arranges, and filters, 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 polarizing 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
Constructed from Water White glass for increased optical clarity
Coated on each side to prevent internal ghosting and reflections
Lightweight and durable aluminum-alloy filter rings
82mm front filter threads allow for use with other filters while helping to preventing vignetting
Index markers indicate different density values for variable neutral density element
Screw-in aluminum-alloy side handle allows the polarizing filter element to be easily rotated
Plastic case for storage and transport, plus microfiber cleaning cloth for filter maintenance