With the variable ND filter on your lens, you can control both the exposure time and depth of field in your photos. Without an ND filter, most cameras do not have a shutter speed fast enough to allow you to shoot wide open in bright conditions. By adding an ND filter, you can blur your background and isolate your subject, even under direct sunlight. You can also shoot very long exposures which is useful for landscape and architecture photography. Exposing your shot for a long period can make people, clouds, cars, and other moving objects seemingly disappear from your images.