Heliopan 58mm Variable Gray Neutral Density Filter (705890) with specialty Schott glass in floating brass ring Heliopans world-renowned Variable Gray Neutral Density Filter appears gray and reduces the amount of light reaching either the digital sensor or film plane. This darkening of the image allows for a longer exposure without offsetting overall color and tonality. Wider apertures and a shorter depth of field make room for optimal foreground and background separation. The Neutral Density filter also performs extremely well under bright light conditions. This enables the user flexibility to maintain constant aperture at slower shutter speeds, making it ideal for capturing movement. Filter Factor: 0.3 To 1.8 (1 To 6 Stops) Our standard 8-Layer Multi-Coating minimizes reflections and does not interfere with the resolution of your camera optics Constructed from the highest German Schott Optics, which guarantees incredible optical resolution. Our glass is specially ground and polished to minimize internal reflections, while ensuring that the quality of your images are not degraded by using our optics in front of your lens. It is also specially hardened to resist most impacts Our precision cut brass ring ensures a secure and sturdy fit, are more resistant to side impacts, and less likely to bind or cross-thread after extended use We do not source any materials outside of Germany in the assembly and construction of our products. All raw materials are prepared and hand-assembled in our factory and do not leave our facility until they are completely inspected by our quality technicians