About ND Filters. Neutral density (ND) filters are the most demanded and essential type of photographic filters because of several reasons. For photographers ND filter means precise control of the amount of light passing through the lens for greater creative control over exposure. For video content creators ND filters helps much to set shutter speeds to match the frame-rate while maintaining the depth-of-field of the footage. Among the varieties of ND filters from ND2 to ND1000 even ND100000 we can generally categorize ND filters into 3 basic groups:. Light density filters (ND2 - ND8). Middle density filters (ND16 - ND200). Deep density filters (ND500 - ND1000 / ND100000). Light density filters will lower the shutter speed in the bright sunny day to allow you to reduce depth of field in very bright light or to use a wider aperture to stay below the diffraction limit.