The Variable Neutral Density Filter, compatible with all analog and digital camera lenses with the popular 55mm filter size, gives you the ability to use fast film in bright outdoor conditions. ND, or neutral density, filters allow you to do a number of things that would otherwise be impossible. By reducing the amount of light, you can record movement in subjects such as waterfalls, clouds, cars, etc. You can also drop your aperture to allow a wider focus, helping separate subjects from their background. This filter offers a range of up to 8 stops of light.