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
Adoption of the Gregorian calendar the date of Easter astronomically using the instant of the vernal equinox and the full moon according to Kepler's "Rudolphine Tables" of 1627; this combination was referred to by the Protestant estates as the "improved calendar" ("Verbesserte Kalender") and considered to be distinct from the Gregorian. They finally adopted the Gregorian calculation of Easter in 1774. The remaining provinces of the Dutch Republic adopted the Gregorian calendar on 12 July 1700 (Gelderland), 12 December 1700 (Overijssel and Utrecht), 12 January 1701 (Friesland and Groningen) and 12 May 1701 (Drenthe). Sweden's transition to the Gregorian calendar was difficult and protracted. Sweden