The Schneider Optics 68-050777 Soft Edge Graduated Neutral Density Filter is used for cinematography. This filter has an ND (Neutral Density) of 0.9 (3 stops) and 50% of the filter is clear. The transition from clear to ND is done with an SE (Soft Edge) transition line. SE grad lines are used with wide angle and normal focal length lenses. This Graduated Neutral Density filter is used to balance exposure within a scene. One very common use is to balance the exposure of the sky and earth in a landscape, thus avoiding overexposed blank white skies.