This 3-stop, 100 X 150MM Hard-Edge Graduated Multi-Coated ND Filter is typically used to help control exposure when shooting with a dark foreground against a bright background such as when shooting a landscape with a bright sky in the shot. Use this 3-stop filter to darken and control exposure in bright areas of the frame while not affecting darker areas. The hard-edge graduation provides a natural-looking transition that is often used with longer lenses. This filter works with 100mm matte boxes, and the extended length allows you to position the transition where you need it to be in the frame.