The Cavision 4 x 4" Enhanced Range ND 0.9 Filter is a neutral density filter with a filter factor of 8x that provides a 3-stop exposure reduction and is compatible with filter holders that can accommodate 2mm thick rectangular filters. Its 0.9 density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required. By increasing your aperture or slowing your exposure time, you can 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.
This filter is uncoated and is constructed from optical glass for clarity as well as color fidelity. Its enhanced range design is intended to maintain image sharpness when used with lenses that feature a focal length of up to 300mm.