These filters offer both amateur and professional photographers Hoya's famous quality at reasonable prices. They have coatings applied to both surfaces to suppress reflection and increase light transmission. The Hoya Multi-Coated Neutral Density (ND) Filter is an essential accessory for any photographer's camera bag. ND filters reduce the amount of visible light that enters the lens, allowing the user to utilize wider apertures or slower shutter speeds, particularly in bright conditions. ND filters work especially well for portraits by allowing the photographer to reduce the depth of field, producing pleasant background blur while keeping the subject in sharp focus. These filters are also often used to emphasize movement by permitting slow shutter speeds in bright light, giving life to photos that would otherwise look frozen in time. Photographing solar eclipses and ultra-bright light sources can be extremely dangerous. This filter reduces light values by 9 stops to less than 1/500th of its original intensity and allows safe photography. It can also be used to achieve super slow shutter speeds in daylight to render moving subjects invisible.