The Cokin H270A Full ND Filter Kit consists of three Neutral Density plain filters and is designed to reduce the amount of light reaching the sensor, without affecting the colour balance. ND filters are generally used when using a long shutter speed to capture smooth motion in water, for example when photographing waves breaking on the shore or waterfalls. They cut the amount of light entering the lens (by 1,2 or 3 stops) so you can get an all-around, well exposed image. The ND2 filter corresponds to a loss of light equivalent to one stop, the ND4 filter is a two stop decrease and the ND8 filter is a three stop decrease, allowing you to gain the aperture you need to enable you to play with backgrounds, distance and depth of field, or to use a slower shutter speed to give an impression of motion. The H270A includes 1 x P-Series Filter Holder, 1 x Cokin P152 Neutral Grey (ND2) P-Series Filter, 1 x Cokin P153 Neutral Grey (ND4) P-Series Filter, 1 x Cokin P154 Neutral Grey (ND8) P-Series Filter.