This B+W Neutral Density Filter reduces the light intensity by three f-stops (log density 0.9). It still features very good color neutrality. This ND filter is especially appropriate for use on video cameras when the lens cannot be stopped down sufficiently in great brightness or when a deliberately low depth of field is desired. The filter factor is 8x.
ND 0.9 (exposure adjustment = 3 stops, reduces ISO 1/8)
Modern high-speed lenses produce bright viewfinder images in reflex cameras and make fast shutter speeds possible in all types of cameras, even with slow-speed films or under poor light conditions. But their large apertures can also be used as an interesting creative element:
At wide apertures the depth of field is reduced so much that eventually only the main subject will be rendered sharply, whereas the fore- and background will be unsharp. This also focuses the attention on the main subject in a creative sense, it draws the attention of the viewer as if by magic, relegating everything else into the background. In intense brightness, how-ever, with high-speed film or a short focal length (with correspondingly higher depth of field), using a large aperture to achieve the desired selective sharpness effect may not be possible without incurring over-exposure. This is when B+W neutral density filters provide the solution.
When the shutter speed is reduced by two or three steps instead opening the aperture, for instance, a neutral density filter can be used for equally creative blur effects with moving subjects.
To enable slow shutter speeds to be used, especially with high speed films, to record movement in subjects such as waterfalls, clouds, or cars
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 (above ISO 400) and allow it to be used outdoors in bright situations
To allow cinema and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which could cause overexposure
Glass type: Schott Glass