The 4 x 4" Cokin NUANCES Z-Pro Series ND Filter features a 4x filter factor that provides a 2-stop exposure reduction and is designed for use with a Cokin Z-Pro Series Filter Holder. Its 0.6 density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required. By slowing your exposure time or increasing your aperture, you are able to control depth of field and convey movement more easily. Neutral density filters do not affect the coloration of the image and are ideal for pairing with other filters.