The Heliopan 72mm Variable Gray Neutral Density Filter appears gray and reduces the amount of light reaching either the digital sensor or film plane. It has no effect on color balance and permits you to capture images such as the rushing movement of a babbling brook or the swirling chaos of city traffic. Since wider apertures are possible, your depth of field will also be minimized as a result when shooting portraits you will be able to achieve more separation between your foreground and background. This filter permits you to shoot your image under bright light conditions at the same aperture but at a slower shutter speed.