Urth Soft Graduated ND8 Lens Filter (Plus+) The Soft Graduated ND8 Lens Filter Plus+ from Urth provides a fixed 3 f-stop light reduction from half your image for balanced exposure and better dynamic range in soft graduated light conditions. By blocking 3 f-stops of light from half the image, you can balance your exposure when the foreground is darker than the background - such as shooting landscapes in the mountains. The soft graduation creates a natural blending of light. The Plus+ range features 20-layers of nano-coating providing easier cleaning and better protection against water, oil, and scratches. These layers also provide a higher maximum light transmission and a more consistent transmission curve for truer light reduction. The filter is double-threaded for stacking filters or using screw-mount lens caps. The B270 Schott optical glass is coated with a 20-layer nano-coating for truer light transmittance, better protection, and easier cleaning. This consciously designed ultra-slim rim avoids vignetting and its durable magnalium is guaranteed for life.