High Quality Content by WIKIPEDIA articles! List of large optical reflecting telescopes. For telescopes larger than 3 meters in aperture see List of largest optical reflecting telescopes. This list combines large or expensive reflecting telescopes from any era, as what constitutes famous reflector has changed over time. In 1900 a 1 meter reflector would be among the largest in the world, but by 2000, would be relatively common for professional observatories.