The 72mm Sion Variable Neutral Density Filter from Vu Filters is a solid variable neutral density filter that provides an exposure reduction of 1 to 5 stops. The 0.3 to 1.5 density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally 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. For easier, repeatable control over density settings, the front ring is also visually demarcated with dots that represent different density values.
This Sion variable neutral density filter is constructed from Schott glass for increased optical clarity and color fidelity. To prevent internal ghosting and reflections, each glass surface includes eight layers of anti-reflection coating. This multicoating also offers greater protection to the filter substrate and helps it to stay clean for longer than with uncoated filters. The Flat Wave Overcoat associated with this Sion solid neutral density filter provides an additional layer over the multicoatings on the front side of the filter, resulting in an improved beading effect to repel water for greater cleaning efficiency.