
The Hoya 52mm Pro-1 Digital ND4 Filter reduces the amount of light entering the lens by 2 f/stops, allowing wider apertures to be selected, which is perfect for portraiture to reduce depth of field. Subject appears crisp & clear while the background becomes a soft blur. Alternatively, the ND4 Filter can be used to allow longer shutter exposures than would otherwise be possible & is widely used for subjects such as waterfalls & other nature scenes to blur the moving elements & emphasize the movement.