Lee 100 Graduated ND Medium Filter - ND 0.9 (3 Stops)The Lee 100mm Neutral Density (ND) 0. 9 Graduated Medium filter enables users to adjust the exposure across the frame by 3 stops, without affecting the colour balance. This filter is ideal for use when elements of the scene protrude into the sky, be that the rooftops of buildings or the peaks of mountains. The nature of the transition between coated and uncoated areas of the filter means that the sky can be filtered with minimal impact on the land