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
Adoption of the Gregorian calendar government in 1912 as the start rather than the regnal year of an emperor. The adopted calendar in both mainland China and Taiwan are called the "Public Calendar" (), or "New Calendar" (). Months in Gregorian calendar in Chinese are rarely named, instead they are usually numbered. For instance, Gregorian calendar December in China are usually written as month 12. On the other hand, in Chinese calendar, the 11th month and 12th month are usually nicknamed. Orally, people are accustomed to call the date in the month as "No. "dd"", for example, the Spring Festival of this year (2017) is