Schmidt camera optical axis of the Schmidt design creates a Schmidt-Newtonian telescope. The addition of a convex secondary mirror to the Schmidt design directing light through a hole in the primary mirror creates a Schmidt-Cassegrain telescope. The last two designs are popular with telescope manufacturers because they are compact and use simple spherical optics. A short list of notable and/or large aperture Schmidt cameras. Schmidt camera A Schmidt camera, also referred to as the Schmidt telescope, is a catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations. The design was invented by Bernhard Schmidt in 1930. Some notable
Gregorian chant consensus that Gregorian chant developed around 750 from a synthesis of Roman and Gallican chants, and was commissioned by the Carolingian rulers in France. Andreas Pfisterer and Peter Jeffery have shown that older melodic essentials from Roman chant are clear in the synthesized chant repertory. There were other developments as well. Chants were modified, influenced by local styles and Gallican chant, and fitted into the theory of the ancient Greek octoechos system of modes in a manner that created what later came to be known as the western system of the eight church modes. The Metz project also invented an