The tokina pro irnd 12 filter is an nd filter with a 16x filter factor that provides a 4 stop exposure reduction its 12 density creates a darkening of the entire image allowing you to photograph with a wider aperture or slower shutter speed than normally required by slowing your exposure time or increasing your aperture you are able to control depth of field and convey movement more easily neutral density filters are intended to not affect the colouration of the image and are ideal for p