ED means "additional-lower dispersion," which refers back to the composition and optical Attributes of the glass used for the lenses. ED glass is specially formulated and has scarce-earth compounds that significantly minimize a visible defect identified as chromatic aberration. This scope is provided inside of a tender, protecting carrying case https://juliuskpuzd.empirewiki.com/7108706/considerations_to_know_about_best_telescopes_for_beginners