The Haida 77mm Slim Pro II Soft-Edge Graduated ND 0.9 Filter helps to darken specific areas of an image, such as bright skies, while allowing for a normal, unaffected exposure in the other regions of the image. The filter is densest at the edge and tapers to clear by the middle, with a soft-edged line of transition between the dense and clear areas. A neutral density filter with a soft-edged line of transition is particularly useful for images that do not have a strongly defined transition between the sky and the foreground. The design of this filter incorporates a rotating mount to allow for precise positioning of the gradation along the horizon line. Neutral density filters do not affect the coloration of the image and the density provides up to a 3-stop reduction in light from entering the lens.