The 72mm NUANCES Variable ND Filter from Cokin is a variable neutral density filter that is designed to mount onto lenses with 72mm front filter threads and provides an exposure reduction of 1 to 8 stops. Its 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 increasing your aperture or slowing your exposure time, you are able to control depth of field and convey movement more easily. For easier, repeatable control over density settings, the front ring is visually demarcated with dots and includes a rotation lever to further enable fast and precise positioning of the front ring. This filter is constructed from Schott B270 glass for increased optical clarity as well as color fidelity, and each glass surface features 16 layers of Cokin's EVERCLEAR 5 anti-reflection coating. These coatings are resistant to oil, dust, dirt, and scratches, offering greater protection to the filter and helping it to stay clean for longer than with uncoated filters. The coatings are also hydrophobic, resulting in an improved beading effect when in contact with water for greater cleaning efficiency.