High Quality Content by WIKIPEDIA articles! This list of the largest optical reflecting telescopes with objective diameters of 3.0 metres (120 in) or greater is sorted by aperture, which is one limit on the light-gathering power and resolution of a reflecting telescope`s optical assembly. The mirrors themselves can be larger than the aperture, and telescopes may use aperture synthesis achieved by interferometry. Telescopes designed to be used as optical astronomical interferometers such as the Keck I and II used together as the Keck Interferometer (up to 85 meters) can reach very high resolutions, although at a narrower range of observations. When the two mirrors are on one mount, the combined mirror spacing of the Large Binocular Telescope (22.8 meters) allows fuller use of the aperture synthesis.