Glossary term: Refracting Telescope
Description: The main optical element of a refracting telescope is a lens, which bundles the incoming light. Such telescopes are still common as amateur telescopes, where special combination of lenses that correct for unwanted color effect ("achromatic telescopes") can make for excellent picture quality for casual observing and for astrophotography. In professional astronomy, refracting telescopes were largely displaced by mirror telescopes from the early 1900s onwards. Astronomers wanted ever larger apertures (lens or mirror diameters), and it is difficult to make refracting telescopes beyond lens sizes of about 1 meter; a telescope lens is "biconvex", i.e. thinner at the rim than in the middle, and since the rim is used to mount the lens, mounting ever larger lenses becomes increasingly difficult.Related Terms:
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Term and definition status: This term and its definition is still awaiting approval
The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".