Telescope Types: Achromatic Telescope, Aerial Telescope, Argunov-Cassegrain Telescope, Cassegrain Reflector, Catadioptric System, Dobso

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 47. Chapters: Achromatic telescope, Aerial telescope, Argunov-Cassegrain telescope, Cassegrain reflector, Catadioptric system, Dobsonian telescope, Fast Fourier Transform Telescope, Graphic telescope, Great refractor, Gregorian telescope, Heliometer, Helioscope, Infrared telescope, Klevtsov-Cassegrain telescope, Korsch telescope, Liquid mirror space telescope, Liquid mirror telescope, List of telescope types, Lurie-Houghton telescope, Maksutov telescope, Meniscus corrector, Modified Dall-Kirkham telescope, Nasmyth telescope, Newtonian telescope, Pfund telescope, Reflecting telescope, Refracting telescope, Ritchey-Chretien telescope, Robotic telescope, Schmidt camera, Schmidt-Cassegrain telescope, Schmidt-Newton telescope, Solar tower (astronomy), Space observatory, Spectrograph, Spectrohelioscope, Sun Gun Telescope, Three-mirror anastigmat, Toroidal reflector, Zenith telescope. Excerpt: A reflecting telescope (also called a reflector) is an optical telescope which uses a single or combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic aberration. Although reflecting telescopes produce other types of optical aberrations, it is a design that allows for very large diameter objectives. Almost all of the major telescopes used in astronomy research are reflectors. Reflecting telescopes come in many design variations and may employ extra optical elements to improve image quality or place the image in a mechanically advantageous position. Since reflecting telescopes use mirrors, the design is sometimes referred to as a "catoptric" telescope. A replica of Newton's second reflecting telescope that he presented to the Royal Society in 1672The idea that curved mirrors behave like lenses dates back at least to Alhazen's 11th century treatise on optics, works that had been widely disseminated in Latin translations in early modern Europe. Soon after the invention of the refracting telescope, Galileo, Giovanni Francesco Sagredo, and others, spurred on by their knowledge of the principles of curved mirrors, discussed the idea of building a telescope using a mirror as the image forming objective. There were reports that the Bolognese Cesare Caravaggi had constructed one around 1626 and the Italian professor Niccolo Zucchi, in a later work, wrote that he had experimented with a concave bronze mirror in 1616, but said it did not produce a satisfactory image. The potential advantages of using parabolic mirrors, primarily reduction of spherical aberration with no chromatic aberration, led to many proposed designs for reflecting telescopes the most notable being James Gregory's 1663 published ideas for what came to be called the Gregorian telescope, but no working models were built until