The Hoya ND 64 reduces light by the equivalent of 6 stops. ABOUT ND FILTERS Neutral density (ND) filters are the most sought-after and important photographic filter types for several reasons. For photographers, ND filters mean precise control of the amount of light that passes through the lens to allow greater creative control of exposure. For video content creators, ND filters are very helpful in adjusting shutter speeds to match frame rates while maintaining the depth of field of the footage. HOYA offers both photographers and filmmakers its own exclusive and wide range of ND filters embedded in the PROND series. PROND filters use HOYA's clear optical glass mounted in a lightweight, precision-machined aluminum frame. The frame features a front filter thread so you can attach additional filters or a lens cap. Thanks to the leading ACCU-ND technology, the image does not experience negative effects from color shifts that can occur due to low-quality materials, low quality control during manufacturing or problems with leakage of the infrared part of the light spectrum. The last problem is the most important in photography and videography today. HOYA's exclusive ACCU-ND technology achieves a uniform reduction of light in the visible and IR spectrum. As a result, the photographer does not have to worry about color shift problems when using HOYA ND filters under different shooting conditions.