A DHG ND filter can control the amount of light and adjust the shutter speed, which is effective in preventing blown out hightlights caused by overexposure and degradation of digital image picture quality caused by excessive stopping-down.\n\nIf the iris of the lens is stopped down drastically, the entire image will become unsharpened (blur small aperture, diffraction phenomenon). ND filter, which can control light volume coming into the lens, can prevent the blurring caused by such an over stopping down, as well as deterioration in image quality caused by overexposure.