The tiffen 55mm ir cut neutral density 30 filter is designed to reduce light from reaching the sensor by up to 10 fstops without affecting colour balance nd filters are primarily used as a photographic tool to control depth of field exposure and enable the use of slower shutter speeds to emphasise movement for instance landscape photographers use nds to create a smooth time past blurred effect in the clouds and water nd filters are also used in the video market to allow cine and video