Schmidt camera 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 examples are the Samuel Oschin telescope (formerly Palomar Schmidt), the UK Schmidt Telescope and the ESO Schmidt; these provided the major source of all-sky photographic imaging from 1950 until 2000, when electronic detectors took over. A recent example is the Kepler spacecraft exoplanet finder. Other related designs are the Wright Camera and Lurie–Houghton telescope. The Schmidt camera was invented by German-Estonian optician
Gregorian chant classes of Gregorian chant have a separate musical formula for each mode, allowing one section of the chant to transition smoothly into the next section, such as the psalm verses that are sung between the repetition of antiphons, or the Gloria Patri. Thus we find models for the recitation of psalmverses, Alleluia and Gloria Patri for all eight modes. Not every Gregorian chant fits neatly into Guido's hexachords or into the system of eight modes. For example, there are chants — especially from German sources – whose neumes suggest a warbling of pitches between the notes E and F, outside