The transmission of the density of grey is approx. 25%. The GND8 (ND0.9) is a graduated grey neutral density filter that helps to specifically darken skies and other bright areas of the image. The design of this filter incorporates a rotating frame to allow precise positioning of the skyline. Neutral Density filters do not affect the coloration of the image and the GND8 (GND0.9) density provides a reduction of 3 stops.