The lee sw150 neutral density nd 09 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 beneath it the lee sw150 filter holder and an ad