The angled-viewing Razor HD 11-33x50 Spotting Scope from Vortex features high-quality glass with specialized optical coatings to provide clear and bright images. The triplet apochromatic lens elements are made of high-density (HD) extra-low dispersion (ED) glass to increase light transmission, minimize distortion, and virtually eliminate chromatic aberration. All air-to-glass surfaces have Vortex's XR anti-reflective coatings to minimize light loss. Additionally, they are ArmorTek coated for scratch resistance. To ensure accurate color across the entire visible spectrum, the Porro prisms are dielectric coated. These coatings are highly reflective and lose less than 1% of the light that passes through them. The use of Porro prisms creates a better depth of view over roof prisms. This combination of coatings and optics creates a spotting scope that produces bright, clear, highly contrasted images with accurate color transmission.