The Hoya ND 4 reduces light by an equivalent of 2 stops. For photographers, ND filters provide precise control over the amount of light entering the lens, allowing for greater creative control over exposure. For video content creators, ND filters are very helpful in setting shutter speeds to adjust frame rates while maintaining the depth of field of the footage. PROND filters use Hoya's clear optical glass, which is mounted in a lightweight, precisely crafted aluminum frame. The frame features a front filter thread, allowing you to attach additional filters or a lens cap. With Hoya's exclusive ACCU-ND technology, a uniform reduction of light in the visible and IR spectrum is achieved. As a result, photographers need not worry about color shifts when using Hoya ND filters under various shooting conditions.