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
Schmidt decomposition of "ρ" on either subsystem have the same spectrum. The strictly positive values "formula_9" in the Schmidt decomposition of "w" are its Schmidt coefficients. The number of Schmidt coefficients of formula_4, counted with multiplicity, is called its Schmidt rank, or Schmidt number. If "w" can be expressed as a product then "w" is called a separable state. Otherwise, "w" is said to be an entangled state. From the Schmidt decomposition, we can see that "w" is entangled if and only if "w" has Schmidt rank strictly greater than 1. Therefore, two subsystems that partition a pure state are entangled if