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available at the time. Over the course of his work for his doctorate degree, Köhler developed a microscope configuration that allowed for an evenly illuminated field of view and reduced optical glare from the light source. It involved a collector lens for the lamp that allowed the light source to be
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had already paved the way for microscope improvements through their contributions to precise optical theory and the development of appropriate glass formulas. Köhler's expertise and his illumination technique helped to improve the microscope optics to achieve optimum resolution, using the entire
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223:, an important principle in optimizing microscopic resolution power by evenly illuminating the field of view. This invention revolutionized light microscope design and is widely used in traditional as well as modern digital imaging techniques today.
330:. He became honorary professor of the Medical Faculty at the University of Jena in 1922 and received an honorary medical doctor degree in 1934. In 1938, he assumed the head position for the Department of Microscopy, Microphotography and Projection.
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on 31 March 1925 (patent number 1649068). His publications include essays on microscopy and projection systems, and in particular his specialty of microphotography. His contributions to biology include fine structure analyses of
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At the time of the invention of his revolutionary illumination scheme as a graduate student at the
University of Giessen, Köhler was working on overcoming problems with microphotography. Microscopes were illuminated by
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467:, microscope applications, and light and dark field illumination, among others. He filed an application for a fixed-ocular microscope of his design in Germany on 16 April 1924, and with the
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As a member of Zeiss, August Köhler filed at least 25 patent applications in Europe as well as at least ten patents in the USA. His patents include projection methods and illumination for
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before going back to university. He started his academic career as a student, instructor and assistant to professor J.W. Spengel at the
Zoological Institute at the university of
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Köhler remained an active staff member of Zeiss for 45 years, contributing numerous innovations during this time. These include the development of a microscope operating with
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in 1994. Today, the Köhler illumination is considered one of the most important principles in achieving the best optical resolution on a light microscope.
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for 45 years and became instrumental to the development of modern light microscope design. From 1922 until his retirement in June 1945, he was also
235:, Germany, where he attended the Ludwig-Georgs-Gymnasium until 1884. He studied at the Technical University in Darmstadt and at the universities of
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and condenser focus control. This superior illumination scheme is still widely used in modern microscopes and forms the basis for
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in 1893, Köhler worked a number of years as a grammar school teacher in Bingen. In 1900, he was invited to join the
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company based on his invention. A century after its first publication, a translation of Köhler's original article,
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one year later. Its significance was not noted until several years later when Köhler was invited to join the
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lenses which allow the specimen to remain in focus when changing objectives on a microscope.
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based on his earlier work on improving microscope illumination. He stayed with Zeiss as a
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In 1888, August Köhler graduated with a teaching degree and subsequently taught at
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207:(4 March 1866 – 12 March 1948) was a German professor and early staff member of
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Köhler's groundbreaking work on microscope illumination was published in the
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Zeitschrift für wissenschaftliche
Mikroskopie und für Mikroskopische Technik
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in 1893 in
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Fundamentals of light microscopy and electronic imaging
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622:Pioneers in optics: August Köhler
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136:honorary doctor degree of the
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267:Teaching and academic career
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227:Early life and education
109:University of Heidelberg
573:Köhler, August (1893).
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441:fluorescence microscopy
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193:Johann Wilhelm Spengel
423:and glass specialist
352:focused on the front
347:using the slow-speed
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114:University of Giessen
689:Carl Zeiss AG people
294:After receiving his
76:Grand Duchy of Hesse
528:Naturwissenschaften
378:confocal microscopy
334:Köhler illumination
304:Zeiss Optical Works
221:Köhler illumination
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127:Köhler illumination
540:10.1007/BF01476460
328:University of Jena
173:University of Jena
138:University of Jena
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68:4 March 1866
674:1948 deaths
669:1866 births
425:Otto Schott
306:company in
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663:Categories
608:: 261–262.
480:References
421:Ernst Abbe
273:gymnasiums
253:mineralogy
237:Heidelberg
217:microscopy
64:1866-03-04
362:diaphragm
358:condenser
349:emulsions
341:gas lamps
320:professor
316:physicist
298:from the
261:chemistry
233:Darmstadt
155:Physicist
96:, Germany
72:Darmstadt
636:Archived
453:parfocal
354:aperture
474:diatoms
356:of the
326:at the
285:limpets
281:Giessen
257:physics
245:zoology
241:Giessen
46:Köhler
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449:tumors
376:, and
277:Bingen
259:, and
249:botany
151:Fields
133:Awards
558:ISBN
322:for
308:Jena
247:and
239:and
213:Jena
94:Jena
83:Died
58:Born
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251:to
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