Overview This NiSi 72mm Circular Long Exposure Filter Kit contains four filters that are compatible with lenses that feature 72mm front filter threads. They can be used individually or in various combinations to create 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. The included filters consist of four solid neutral density filters that reduce the amount of light entering a lens by 3, 10, and 15 stops, as well as a filter that combines a solid neutral density effect with a circular polarizer effect. When in use, the solid neutral density and circular polarizer filter provides a 6-stop exposure reduction while helping to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface. A filter pouch is included to store and transport this filter kit. It features four padded, nonabrasive pockets plus a touch-tab-fastened closure.