The pl fader variable nd filter from kenko uses two high transparency polarising film layers to control the amount of light that passes through the filter and into the lens by rotating the outer frame any value of neutral density from ndx3 to ndx400 between 1 8 stops can be achieved reducing the amount of light reaching your sensor gives you more control over aperture shutter speed and depth of field so you can capture be more creative with your photography and get the effect you desire t