Reduces light entering the camera by 10 stops
The Tiffen IR Cut ND 3.0 is a Neutral Density filter providing 10-stop exposure absorption. The high density blocks light emission of the visual spectrum into the camera, allowing you to photograph with a much slower shutter speed or at a wider aperture than required. This gives the photographer two techniques; the filter is ideal then for long exposures in which anything with movement in the image is desired to appear blurred. The second is in which the photographer needs to use faster or more wide open lens apertures to create less depth of field.
The IR blocker allows for less Infra-Red pollution which has been attributed to long exposures on smaller crop sensors.