Carl Kellner (March 26, 1826 – May 13, 1855) was a German mechanic and
self-educated 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 cameras.
Biography
Carl Kellner was born in
Hirzenhain,
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 dis ...
, in
Hesse
Hesse or Hessen ( ), officially the State of Hesse (), is a States of Germany, state in Germany. Its capital city is Wiesbaden, and the largest urban area is Frankfurt, which is also the country's principal financial centre. Two other major hist ...
. 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 that 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 equipment, 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 ...
s. Kellner had invented a new
achromatic 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 Optical telescope, telescopes and microscopes. It is named because it is usually the lens that is closest to the eye when someone looks thro ...
, published in his treatise ''Das orthoskopische Ocular, eine neu erfundene achromatische Linsencombination'', that was able to produce an image with correct
perspective 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 (February 27, 1829 – May 9, 1869), who from then on managed the company. In 1864,
precision mechanic Ernst Leitz I 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 microscope was a market success.
See also
*
Leica Camera
References
Milestones of Leica by
Wild Leitz AG.
*
The development of 35mm photography', Times Journal of Photography, July 2002.
*
Leitz, 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
19th-century German mathematicians