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 'Alleluia'. The Alleluia is also in two parts, the alleluia proper and the psalmverse, by which the Alleluia is identified (Alleluia V. Pascha nostrum). The last melisma of the verse is the same as the jubilus attached to the Alleluia. Alleluias are not sung during penitential times, such as Lent. Instead, a Tract is chanted, usually with texts from the Psalms. Tracts, like Graduals, are highly centonized. Sequences are sung poems based on couplets. Although many sequences are not part of the liturgy and thus not part of the Gregorian repertory proper, Gregorian sequences include such well-known chants as "Victimae