Reduction of the light incidence by 75 %The neutral-density filter ND 4 from walimex with a value of 0.6 reduces the light incidence by 75 % or 2 apertures. With this neutral-density filter you can film with open aperture even in bright sunlight or daylight. This is why it is preferably used if a blurring background is to be achieved despite bright sunlight. With its size of 4 x 4 it fits many Matte boxes, e.g. also for the walimex pro Director II. The filter is in this case simply pushed into the filter slot of the Matte box.