Heliopan 58mm Graduated Neutral Density 2x (705867) Heliopan's world-renowned Graduated Neutral Density Filter enables the user to regain control over unideal light conditions. GND filters have the acute ability to balance light intensity in one part of a scene with another while transitioning between the two, often imperceptibly. This is especially important under bright light conditions where a properly exposed foreground results in an washed-out, over-exposed sky while exposing for the sky will leave the foreground too dim and under-exposed. Graduated Neutral Density Factors: GND.3 (exposure factor = 2x; exposure adjustment = 1 stop; reduces ISO 1/2), GND.6 (exposure factor = 4x; exposure adjustment = 2 stops; reduces ISO 1/4), GND.9 (exposure factor = 8x; exposure adjustment = 3 stops; reduces ISO 1/8) 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