Cavision 4x5.65" Enhanced Range Solid Neutral Density 1.2 Glass Filter, 4 Stop

The neutral density filter reduces the amount of light entering the lens, without effecting color. It is used primarily when the light level exceeds that which the film stock or video CCD can handle; this is often the case when shooting on a sunny day in a location featuring an abundance of light reflection such a desert, ocean or snowy landscape. If a reduction in depth of field is desired, the ND filter can help achieve this because it allows you to open the lens aperture further without changing exterior light levels. ND filters come in increments of 0.3, where each increment is equivalent to one stop. For example, if a scene is overexposed by 2 stops use a 0.6 ND filter to get proper exposure.