The Lee Seven5 Graduated Neutral Density 0.3 Soft Filter features a soft graduation and is designed to reduce exposure by 1 stop without affecting colour balance. Neutral density graduated filters enable you to balance light intensity in one part of a scene with another. For example, when photographing a landscape in which the sky is much brighter than the foreground, placing the neutral density part of the filter onto the sky in the frame will reduce the sky exposure without affecting the foreground. This enables cloud detail to be kept correctly exposed and avoids the ""white out"" effect caused by exposing for the foreground. The Seven5 Graduated Neutral Density 0.3 Soft filter is 75x90mm in size and fits in the Lee Seven5 filter holder. In order to use this filter you will need to purchase the correct size Seven5 adapter ring for your lens (check lens for thread size) and the Seven5 filter holder, both are available separately.