Phottix Variable ND Multi-Coated Filter (VND-MC) 72mm Cut the light reaching your sensor by 2-8 stops. The Phottix VND-MC Variable ND Filter screws on like a regular lens filter and is completely adjustable. Do away with static ND filters and change density as the environment changes. Focusing is much easier with a VND then with a tradition ND filter. Turn the ND down to focus, turn it back up to take the shot - much easier than taking a filter out of the holder and adding it back again. These filters have 12 layers of multi-coating (6+6) for clearer images with less haze. How can a VND filter be used? -Variable 2-8 stops of variable density -Reduce brightness without affecting color or depth of field -Enable slower shutter speeds to cause blurring effect in water, clouds or cars. -Decrease depth of field by allowing large apertures to be used while keeping shutter speeds lower. -For DSLR Video: Help optimize your shutter speed - keeping it double your FPS rate. -When using film: Decrease the sensitivity of high speed ISO films in bright outdoor conditions.