Refractor

A telescope that gathers light with a lens. The original design showed dramatic rainbows, or ‘false color,” around stars and planets. Most modern refractors are achromatic, meaning ‘free of false color,” but this design still shows thin violet fringes around the brightest objects. The finest refractors produced today are apochromatic, meaning ‘beyond achromatic.” They use expensive, exotic kinds of glass to reduce false color to nearly undetectable levels.