Hoya 67mm NDx4 HMC Neutral Density Filter

To enable slow shutter speeds to be used to record mo.. To enable slow shutter speeds to be used to record movement in subjects such as waterfalls, clouds, cars, etc To decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their background To decrease the effective ISO of high speed film (ie: above ISO400) and allow it to be used outdoors in bright situations To allow video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which would normally cause overexposure + more