The Hoya 72mm ProND500 Filter is a solid neutral density filter that enables a 9-stop increase in exposure. This 2.7 density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required. This filter employs Hoya's metallic ACCU-ND coating on both sides of the substrate to create the neutral density effect and ensure maintained color neutrality between filter grades. It is constructed from high-quality clear optical glass for notable image clarity and is set within a durable one-piece aluminum filter ring.