Julius Scheiner (25 November 1858 – 20 December 1913) was a German

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

, born in

Cologne Cologne ( ; ; ) is the largest city of the States of Germany, German state of North Rhine-Westphalia and the List of cities in Germany by population, fourth-most populous city of Germany with nearly 1.1 million inhabitants in the city pr ...

and educated at

Bonn Bonn () is a federal city in the German state of North Rhine-Westphalia, located on the banks of the Rhine. With a population exceeding 300,000, it lies about south-southeast of Cologne, in the southernmost part of the Rhine-Ruhr region. This ...

. He became assistant at the astrophysical observatory in

Potsdam Potsdam () is the capital and largest city of the Germany, German States of Germany, state of Brandenburg. It is part of the Berlin/Brandenburg Metropolitan Region. Potsdam sits on the Havel, River Havel, a tributary of the Elbe, downstream of B ...

in 1887 and its observer in chief in 1898, three years after his appointment to the

chair A chair is a type of seat, typically designed for one person and consisting of one or more legs, a flat or slightly angled seat and a back-rest. It may be made of wood, metal, or synthetic materials, and may be padded or upholstered in vario ...

astrophysics Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the ...

in the

University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

. Scheiner paid special attention to celestial photography and wrote ''Die Spektralanalyse der Gestirne'' (1890); ''Lehrbuch der Photographie der Gestirne'' (1897); ''Strahlung und Temperatur der Sonne'' (1899); ''Der Bau des Weltalls'' (1901); third edition (1909). In 1899 he began the publication of the ''Photographische Himmelskarte; Zone +31° bis +40° Deklination''. He is also credited with developing the first system for measuring the sensitivity of photographic emulsions in 1894,Martin Riat. ''Graphische Techniken - Eine Einführung in die verschiedenen Techniken und ihre Geschichte''. E-Book, 3. German edition, Burriana, spring 2006

, based on a Catalan book: Martin Riat. ''Tècniques Gràfiques: Una introducció a les diferents tècniques i a la seva història''. 1. edition, Aubert, September 1983, . Scheinergrade, which also inspired the later DIN 4512 standard to measure

film speed Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system introduced in 1974. A closely related system, also known as IS ...

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A Spanish version of the book 'Técnicas Gráficas' can be downloaded freely from this site.
19th-century German astronomers German science writers 1858 births 1913 deaths German male non-fiction writers 20th-century German astronomers Academic staff of the Humboldt University of Berlin {{Germany-astronomer-stub

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