The NiSi 77mm HUC PRO Nano IR Neutral Density Filter ND8 (0.9) 3 Stop is specially designed to reduce the light entering the camera by 3 stops. This filter is made of high quality optical glass with nano coating to avoid loss of details. Neutral density filters do not affect the coloration of the image, and the 0.9 density provides 3-point reduction of light entering the lens. The ND filter darkens the entire image, allowing you to shoot with a larger aperture or slower shutter speed than is normally required. By slowing down the shutter speed or increasing the aperture, you can control the depth of field and convey movement in your images. ND8 is often used to capture the flow of water in marine images and to create larger apertures when using flash outdoors.