To minimize chromatic aberration (color blur) that occurs in long focal length lenses, the [PROMINAR] telephoto lens utilizes one pure fluorite crystal lens and two XD (eXtra-low-Dispersion) lenses. Bringing together the advanced optical technology fostered through decades of spotting scope development with the use of a fluorite crystal lens has produced a camera lens with extremely high contrast and sharp images. Making effective use of the outstanding optical system of the master lens, the telephoto lens can also be used as a spotting scope by connecting it to the optional prism unit and eyepiece. Through the use of a simple and easy to use bayonet mounting system, switching between “photographing” and “observation” with the lens is easily accomplished. When used as a spotting scope, crystal clear images can be enjoyed since there is no focusing screen. ▲TOP