The Tiffen 4 x 4" ND 0.9 Filter is a solid neutral density filter providing a 3-stop exposure reduction. This 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 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.
This filter is made using ColorCore technology, a process that involves laminating the filter substrate between two pieces of optical glass and grinding flat to a tolerance of 1/10,000th of an inch. This filter measures 4 x 4" / 101.6 x 101.6mm.