Gray filters, also called ND (Neutral Density) filters, reduce the entire, visible light spectrum evenly across the entire filter. Colors and contrasts are not affected. This reduction is useful in various applications. For example, a longer exposure time can lead to flare effects with moving water or can be processed with an open aperture and extended shutter speed in a bright environment. The gray filter used here with a filter factor of 8 extends the exposure time / aperture extension by the aperture value of 3. The ND filter has excellent optical properties. The high-quality lenses are embedded in a precisely manufactured metal mount. The filter has an additional front thread, which makes combinations possible. It is transported in a protective case.