Neutral Density of 0.6 (2 stops) to 0.9 (3 stops). The transition from clear to ND is done with a Soft Edge (SE) transition line. Soft Edge grad lines are used with wide angle and normal focal length lenses. Graduated Neutral Density filters are used to balance exposure within a scene. One very common use is to balance the exposure of sky and earth in a landscape, avoiding overexposed, blank white skies.