High Quality Content by WIKIPEDIA articles! Large Binocular Telescope (LBT) is an optical telescope for astronomy located on Mount Graham (10,700-foot (3,300 m)) in the Pinaleno Mountains of southeastern Arizona, and is a part of the Mount Graham International Observatory. The LBT is currently one of the world`s most advanced optical telescopes; using two 8.4 m (27 ft) wide mirrors can give the same light gathering ability as a 11.8 m (39 ft) wide single circular telescope and detail of 22.8 m (75 ft) wide one. Either of its mirrors would be the largest optical telescope in continental North America. Strehl ratios of 60-90% at H band and 95% at M band have been achieved by the LBT.