Carl Kellner (March 26, 1826 – May 13, 1855) was a German mechanic and

self-educated Autodidacticism (also autodidactism) or self-education (also self-learning and self-teaching) is education without the guidance of masters (such as teachers and professors) or institutions (such as schools). Generally, autodidacts are individu ...

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

who founded in 1849 an "Optical Institute" that later became the Leitz company, makers of the

Leica Leica Camera AG () is a German company that manufactures cameras, optical lenses, photographic lenses, binoculars, rifle scopes and microscopes. The company was founded by Ernst Leitz in 1869 (Ernst Leitz Wetzlar), in Wetzlar, Germany. ...

cameras.

Biography

Carl Kellner was born in

Hirzenhain Hirzenhain is a municipality in the Wetteraukreis, in Hesse, Germany. It is located approximately 45 kilometers northeast of Frankfurt am Main. It has a population of around 2,800. History From 1943 to 1945 the area was the site of '' :de:Arbeits ...

Wetteraukreis The Wetteraukreis is a ''Kreis'' (district) in the middle of Hesse, Germany. Neighbouring districts are Landkreis Gießen, Vogelsbergkreis, Main-Kinzig-Kreis, district-free Stadt Frankfurt, Hochtaunuskreis and Lahn-Dill-Kreis. History The distr ...

, in

Hesse Hesse (, , ) or Hessia (, ; german: Hessen ), officially the State of Hessen (german: links=no, Land Hessen), is a state in Germany. Its capital city is Wiesbaden, and the largest urban area is Frankfurt. Two other major historic cities are Da ...

. In 1849 he founded in

Wetzlar Wetzlar () is a city in the state of Hesse, Germany. It is the twelfth largest city in Hesse with currently 55,371 inhabitants at the beginning of 2019 (including second homes). As an important cultural, industrial and commercial center, the un ...

a company called ''"Optisches Institut"'' for the production of

lenses A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements ...

and

microscope A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...

s. Kellner had invented a new

achromatic Achromatic means literally “without color”. It may refer to: * Achromatic colors, “greys” or “neutral colors”, also black or white * Achromatic lens, a lens designed to minimize chromatic aberration * Achromatic vision: ** Monochroma ...

combination of lenses for an

eyepiece An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is named because it is usually the lens that is closest to the eye when someone looks through the device. The ...

, published in his treatise ''Das orthoskopische Ocular, eine neu erfundene achromatische Linsencombination'', that was able to produce an image with correct

perspective Perspective may refer to: Vision and mathematics * Perspectivity, the formation of an image in a picture plane of a scene viewed from a fixed point, and its modeling in geometry ** Perspective (graphical), representing the effects of visual per ...

and without the distortions that were usual for other optical instruments of the time. His invention is still useful and known as the Kellner eyepiece.

Legacy

After his early death in Wetzlar in 1855 from tuberculosis at the age of 29, his widow led the company, which had twelve employees at that time. In 1856, she married her employee

Friedrich Belthle Friedrich may refer to: Names *Friedrich (surname), people with the surname ''Friedrich'' *Friedrich (given name), people with the given name ''Friedrich'' Other *Friedrich (board game), a board game about Frederick the Great and the Seven Years' ...

(February 27, 1829 – May 9, 1869), who from then on managed the company. In 1864,

precision mechanic Precision mechanics (also "fine mechanics") is an engineering discipline that deals with the design and construction of smaller precision machines, often including measuring and control mechanisms of different kinds. The study may be further defi ...

Ernst Leitz I Ernst Leitz II (1 March 1871 – 15 June 1956) was a German business person and humanitarian. He was the second head of the optics company now known as Leica Camera and organized the Leica Freedom Train to allow people, most of whom were Jewish, ...

joined them; he became a partner on October 7, 1865, took over the company in 1869 and re-founded it as the ''Ernst Leitz GmbH''. The company expanded quickly; its newly developed

binocular Binocular may refer to: Science and technology * Binocular vision, seeing with two eyes * Binoculars, a telescopic tool * Binocular microscope, binocular viewing of objects through a single objective lens Other uses * Binocular (horse), a thoroug ...

microscope was a market success.

References

Milestones of Leica
by

Wild Leitz AG Wild, wild, wilds or wild may refer to: Common meanings * Wild animal * Wilderness, a wild natural environment * Wildness, the quality of being wild or untamed Art, media and entertainment Film and television * ''Wild'' (2014 film), a 2014 A ...

. *
The development of 35mm photography
', Times Journal of Photography, July 2002.

*

Leitz Leitz may refer to several German companies: * Esselte Leitz GmbH & Co KG, founded by Louis Leitz in 1896, a German manufacturer of office products ** Louis Leitz (1846–1918), German inventor and founder of Esselte Leitz GmbH & Co KG * Leitz GmbH ...

, in German. {{DEFAULTSORT:Kellner, Carl 1826 births 1855 deaths Businesspeople from Hesse People from Wetzlar Lens designers German businesspeople in the healthcare industry German scientific instrument makers

Biography

Legacy

See also

References