Bernhard Schmidt
Encyclopedia
Bernhard Woldemar Schmidt (March 30, 1879 – December 1, 1935) was a German
optician
. In 1930 he invented the Schmidt telescope
which corrected for the optical errors of spherical aberration
, coma, and astigmatism, making possible for the first time the construction of very large, wide-angled reflective cameras of short exposure time for astronomical research.
(now belonging to Viimsi Parish), off the coast of Reval (Tallinn)
, Estonia
, then part of the Russian Empire
. The inhabitants of this island, mainly Estonian Swedes, generally spoke Swedish
or Estonian
, but the Schmidt family also spoke German
. Bernhard was the oldest of six children, three boys (one of whom died in infancy) and three girls.
Nargen was a small, rural island whose population mainly supported themselves through fishing and piloting ships into the port of Reval. With his younger brother August Fredrik, Bernhard Schmidt engaged in many childhood adventures on the island. He was an extremely inquisitive, inventive, and imaginative young person and adult. For example, when young he built his own camera from a purchased lens and old concertina bellows and succeeded in photographing his local surroundings and various family members, and even sold some of his photos. He also became fascinated with the night sky and constellations.
Another adventure proved tragic and marked Schmidt for the rest of his life. When he was 15 years old, he experimented with gunpowder
. He packed an iron pipe with a charge, but through a mistake with the fuse the pipe exploded, and he lost the thumb and index finger of his right hand. Despite his mother's attempts to clean and bandage the wounds, surgeons in Tallinn later amputated the whole hand. This event appears to have deepened his reserve
and introspection, qualities well noted by his contemporaries in later life.
, Sweden
, to study at the Chalmers University of Technology
, but soon thereafter switched to the University of Mittweida in the Kingdom of Saxony
to further his education.
, and Karl Schwarzschild
realized the excellence of Schmidt's mirrors for their researches.
Astrophysical Observatory. As his business increased, he hired several assistants, two of whom have left valuable accounts of Schmidt's working methods. Schmidt also bought an automobile, a rare luxury then, and employed a friend as chauffeur. Using a long focus horizontal mirror and a plane coelostat, both of his own manufacture, he took impressive photos of the sun, moon, and major planets. When one considers that he did much of the fabrication literally using just one hand, it is difficult not to be astonished at Schmidt's skill.
World War I
brought the boom to an end. Schmidt was arrested as an enemy-alien, as Estonia belonged to the Russian Empire, and was sent to an internment camp for about six months. After his release, he remained under police control and some of his suspicious-looking astronomical equipment was confiscated. He attempted to continue his business, but as the war dragged on and turned to defeat for Germany, the economy became grim and scientists had no money for astronomy. The situation did not improve after the war because of the political turmoil in Germany and the need to pay war reparations. Inflation galloped out of control in 1923 and many people lost their entire savings. By the mid-1920s, Schmidt's business was ruined and he had to liquidate his remaining equipment as junk.
, the director of the Hamburg Observatory, a facility located outside Hamburg
in the countryside near the village of Bergedorf
. Schorr had become interested in Schmidt's horizontal mirror and coelostat telescope and ordered one to be built for his observatory. After the war when Schmidt's economic situation became increasingly difficult, Schmidt began making overtures to Schorr for some kind of work at the observatory. Schorr had only a little to offer: Schmidt could come to Bergedorf and lodge for free; there was repair work to do on the horizontal telescope, for which he would be paid a small fee. This was in 1926. For a time Schmidt did not accept. He had a number of patents to his credit, one of which involved using a wind-driven propeller to power boats forward. Schmidt hoped to turn this invention into something profitable. He also went back to Estonia for a family visit and to scout out opportunities in optics, as Estonia had become an independent republic after World War I.
Nothing came of these efforts, and by 1927 Schmidt's prospects were so poor that he accepted Schorr's offer. He began to establish a workshop in the basement of the Main Service Building at the observatory and to repair the horizontal telescope. During 1927 and 1929, Schmidt participated in two solar eclipse expeditions mounted by the Hamburg Observatory, the first to northern Sweden and the second to the Philippines
. It was during this second trip that Schmidt announced to his companion, the astronomer Walter Baade
, the most important invention of Schmidt's lifetime, indeed an invention that revolutionized astronomy and optical design in the second half of the 20th century, namely his wide-angle reflective camera.
Unfortunately, the only large aperture wide-field telescopes before Schmidt were ordinary reflecting telescopes of short focal ratio (about f/3), and these presented images which while sharp at the middle of their fields of view, quickly lost their definition away from the field center. Star images became bloated and comet-shaped, with the head of the "comet" pointing to the middle of the photographic field. This bloating results mainly from the optical aberrations (i.e. errors) called "coma" and "astigmatism." Before Schmidt it was impossible to build a large, fast reflector telescope which was not plagued by these errors.
Schmidt was well-aware of this and had been pondering possible solutions during the late 1920s. According to Baade, he had abandoned at least one solution already, when finally he hit upon his ultimate design, which involved a novel, indeed bold departure from traditional optical designs. Schmidt realized that by employing a large spherically shaped mirror (instead of the normal paraboloidal mirror of a reflector telescope) and a smaller apertured diaphragm placed at the center of curvature of the mirror, he could at a stroke eliminate coma and astigmatism. He would be left, however, with spherical aberration which is just as damaging to image sharpness.
His boldness lies in realizing that he could eliminate the spherical aberration by placing a thin, very weakly curved aspheric lens
(now called the "Schmidt corrector plate
") at the same center of curvature as the apertured diaphragm. This aspheric lens has a complex curve that is convex near its middle and concave near its periphery that creates the opposite spherical aberration of the spherical mirror it is paired with, canceling out the mirror's spherical aberration. In this way, very neatly and simply he could construct a large camera of f/1.75 or even faster, that would give sharp images across a field more than 15 degrees in diameter, making it possible to image large swathes of sky with short exposures (on the order of a few minutes versus an hour or more with a conventional reflector). His first camera had an aperture of about 360mm or 14.5" in diameter, and a focal ratio of f/1.75. It is now housed in a museum at the Hamburg Observatory. Schmidt's combining of diverse optical elements (a special mirror, a diaphragm at a particular location, and a "correction plate") into a simple catadioptric
system, based on reasoning from first principles, was epoch making. In particular, the "correction plate" was like nothing ever seen before in telescope design. After Schmidt a flood of new catadioptric designs appeared in the subsequent decades.
Schmidt published a brief account (in German
) of his invention in professional publications, and offered to build his cameras for professional observatories. Unfortunately, his publicity was too little and his design was too novel. Moreover, the invention coincided with the beginning of the Great Depression
. No orders came in and he remained dependent on Schorr and Bergedorf for a modest income from occasional jobs till the end of his life. He produced a larger camera in 1934 and reground the 60cm Bergedorf-Steinheil photographic refractor as well.
Schmidt fell ill at the end of November 1935 after a business trip to Leiden in the Netherlands
. Despite attempts at treatment, he died on December 1, 1935 at the age of 56. An autopsy
revealed that he was suffering from a lung infection.
Schmidt never married and had no children. Soon after his death through the advocacy of Walter Baade
when he arrived at the Mount Wilson Observatory
in the United States, the Schmidt telescope idea took off. An 18" Schmidt was produced in 1938 and then ten years later, the famous 48" (122 cm) Samuel Oschin telescope
Schmidt-telescope was built at Mount Palomar Observatory. This last telescope produced a flood of new observations and information. It proved the brilliance of the Schmidt concept beyond doubt.
Subsequently at Bergedorf in 1955 a large, well-constructed Schmidt was dedicated. The 2-meter Schmidt telescope of the Karl Schwarzschild Observatory
was built later and remains the largest Schmidt camera in the world, although more technologically advanced versions have since been produced. The Bergedorf Schmidt was moved to Calar Alto Observatory
in 1976.
B. Schmidt is also the protagonist of the biographic novel Vastutuulelaev by Estonian author Jaan Kross
.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
optician
Optician
An optician is a person who is trained to fill prescriptions for eye correction in the field of medicine, also known as a dispensing optician or optician, dispensing...
. In 1930 he invented the Schmidt telescope
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. Other similar designs are the Wright Camera and Lurie-Houghton telescope....
which corrected for the optical errors of spherical aberration
Spherical aberration
thumb|right|Spherical aberration. A perfect lens focuses all incoming rays to a point on the [[Optical axis|optic axis]]. A real lens with spherical surfaces suffers from spherical aberration: it focuses rays more tightly if they enter it far from the optic axis than if they enter closer to the...
, coma, and astigmatism, making possible for the first time the construction of very large, wide-angled reflective cameras of short exposure time for astronomical research.
Childhood
Schmidt was the son of Carl Constantin and Marie Helene Christine (née Rosen) Schmidt. He grew up on the island of NargenNaissaar
Naissaar is an island northwest of Tallinn in Estonia. The island covers an area of 18.6 km². It is 13-14 km long and 6 km wide, and lies about 8.5 km from the mainland. The highest point on the island is Kunilamägi, which is 27 meters above sea-level. The island consists predominantly of...
(now belonging to Viimsi Parish), off the coast of Reval (Tallinn)
Tallinn
Tallinn is the capital and largest city of Estonia. It occupies an area of with a population of 414,940. It is situated on the northern coast of the country, on the banks of the Gulf of Finland, south of Helsinki, east of Stockholm and west of Saint Petersburg. Tallinn's Old Town is in the list...
, Estonia
Governorate of Estonia
The Governorate of Estonia or Estland, also known as the Government of Estonia or Province of Estonia, was a governorate of the Russian Empire in what is now northern Estonia.-Historical overview:...
, then part of the Russian Empire
Russian Empire
The Russian Empire was a state that existed from 1721 until the Russian Revolution of 1917. It was the successor to the Tsardom of Russia and the predecessor of the Soviet Union...
. The inhabitants of this island, mainly Estonian Swedes, generally spoke Swedish
Swedish language
Swedish is a North Germanic language, spoken by approximately 10 million people, predominantly in Sweden and parts of Finland, especially along its coast and on the Åland islands. It is largely mutually intelligible with Norwegian and Danish...
or Estonian
Estonian language
Estonian is the official language of Estonia, spoken by about 1.1 million people in Estonia and tens of thousands in various émigré communities...
, but the Schmidt family also spoke German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....
. Bernhard was the oldest of six children, three boys (one of whom died in infancy) and three girls.
Nargen was a small, rural island whose population mainly supported themselves through fishing and piloting ships into the port of Reval. With his younger brother August Fredrik, Bernhard Schmidt engaged in many childhood adventures on the island. He was an extremely inquisitive, inventive, and imaginative young person and adult. For example, when young he built his own camera from a purchased lens and old concertina bellows and succeeded in photographing his local surroundings and various family members, and even sold some of his photos. He also became fascinated with the night sky and constellations.
Another adventure proved tragic and marked Schmidt for the rest of his life. When he was 15 years old, he experimented with gunpowder
Gunpowder
Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...
. He packed an iron pipe with a charge, but through a mistake with the fuse the pipe exploded, and he lost the thumb and index finger of his right hand. Despite his mother's attempts to clean and bandage the wounds, surgeons in Tallinn later amputated the whole hand. This event appears to have deepened his reserve
and introspection, qualities well noted by his contemporaries in later life.
Youth
In spite of his loss, Schmidt was soon experimenting and inventing again. He built a dynamo and got August to crank it. He also took more photos and became adept at developing and printing them. In 1895 he moved to Reval, and for a time worked at retouching photographs. Later he worked for the Volta Electrical Motor Works and became skilled in drafting. In 1901 he went to GothenburgGothenburg
Gothenburg is the second-largest city in Sweden and the fifth-largest in the Nordic countries. Situated on the west coast of Sweden, the city proper has a population of 519,399, with 549,839 in the urban area and total of 937,015 inhabitants in the metropolitan area...
, Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
, to study at the Chalmers University of Technology
Chalmers University of Technology
Chalmers University of Technology , is a Swedish university located in Gothenburg that focuses on research and education in technology, natural science and architecture.-History:...
, but soon thereafter switched to the University of Mittweida in the Kingdom of Saxony
Kingdom of Saxony
The Kingdom of Saxony , lasting between 1806 and 1918, was an independent member of a number of historical confederacies in Napoleonic through post-Napoleonic Germany. From 1871 it was part of the German Empire. It became a Free state in the era of Weimar Republic in 1918 after the end of World War...
to further his education.
Adulthood
During this period his interest in astronomy and optics increased. In Mittweida he had hoped to study with Dr. Karl Strehl, a noted optical theorist. Strehl, however, had recently departed. Gradually, Schmidt found his true calling, namely the grinding and polishing of highly precise optics for astronomical applications. He seems to have begun the grinding of mirrors sometime around 1901, and thereafter began to sell some of his products to amateur astronomers. By March 1904, he had made so much progress in his new endeavor that after finishing his studies, he was soon in contact with professionals at the major observatories in Germany. His business rapidly took off when noted astronomers such as Hermann Carl VogelHermann Carl Vogel
Hermann Carl Vogel was a German astronomer. He was born in Leipzig, Kingdom of Saxony.Vogel pioneered the use of the spectroscope in astronomy...
, and Karl Schwarzschild
Karl Schwarzschild
Karl Schwarzschild was a German physicist. He is also the father of astrophysicist Martin Schwarzschild.He is best known for providing the first exact solution to the Einstein field equations of general relativity, for the limited case of a single spherical non-rotating mass, which he accomplished...
realized the excellence of Schmidt's mirrors for their researches.
Mittweida years
Between 1904 and 1914, Schmidt's business boomed and he acquired an immense reputation in Germany. Not only did he produce some of the most difficult and precise mirrors ever attempted up to that time, but he was entrusted with correcting and improving lenses originally supplied by famous optical houses, for example the 50cm Steinheil visual refractor at the PotsdamPotsdam
Potsdam is the capital city of the German federal state of Brandenburg and part of the Berlin/Brandenburg Metropolitan Region. It is situated on the River Havel, southwest of Berlin city centre....
Astrophysical Observatory. As his business increased, he hired several assistants, two of whom have left valuable accounts of Schmidt's working methods. Schmidt also bought an automobile, a rare luxury then, and employed a friend as chauffeur. Using a long focus horizontal mirror and a plane coelostat, both of his own manufacture, he took impressive photos of the sun, moon, and major planets. When one considers that he did much of the fabrication literally using just one hand, it is difficult not to be astonished at Schmidt's skill.
World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
brought the boom to an end. Schmidt was arrested as an enemy-alien, as Estonia belonged to the Russian Empire, and was sent to an internment camp for about six months. After his release, he remained under police control and some of his suspicious-looking astronomical equipment was confiscated. He attempted to continue his business, but as the war dragged on and turned to defeat for Germany, the economy became grim and scientists had no money for astronomy. The situation did not improve after the war because of the political turmoil in Germany and the need to pay war reparations. Inflation galloped out of control in 1923 and many people lost their entire savings. By the mid-1920s, Schmidt's business was ruined and he had to liquidate his remaining equipment as junk.
Bergedorf
From 1916 onward Schmidt had been in contact with Professor Richard SchorrRichard Schorr
Richard Reinhard Emil Schorr , was an astronomer. The lunar crater Schorr and the asteroid 1235 Schorria are named after him....
, the director of the Hamburg Observatory, a facility located outside Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...
in the countryside near the village of Bergedorf
Bergedorf
Bergedorf is the largest of the seven boroughs of Hamburg, Germany and a quarter within this borough. In 2006 the population of the borough was 118,942.-History:...
. Schorr had become interested in Schmidt's horizontal mirror and coelostat telescope and ordered one to be built for his observatory. After the war when Schmidt's economic situation became increasingly difficult, Schmidt began making overtures to Schorr for some kind of work at the observatory. Schorr had only a little to offer: Schmidt could come to Bergedorf and lodge for free; there was repair work to do on the horizontal telescope, for which he would be paid a small fee. This was in 1926. For a time Schmidt did not accept. He had a number of patents to his credit, one of which involved using a wind-driven propeller to power boats forward. Schmidt hoped to turn this invention into something profitable. He also went back to Estonia for a family visit and to scout out opportunities in optics, as Estonia had become an independent republic after World War I.
Nothing came of these efforts, and by 1927 Schmidt's prospects were so poor that he accepted Schorr's offer. He began to establish a workshop in the basement of the Main Service Building at the observatory and to repair the horizontal telescope. During 1927 and 1929, Schmidt participated in two solar eclipse expeditions mounted by the Hamburg Observatory, the first to northern Sweden and the second to the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
. It was during this second trip that Schmidt announced to his companion, the astronomer Walter Baade
Walter Baade
Wilhelm Heinrich Walter Baade was a German astronomer who worked in the USA from 1931 to 1959.-Biography:He took advantage of wartime blackout conditions during World War II, which reduced light pollution at Mount Wilson Observatory, to resolve stars in the center of the Andromeda galaxy for the...
, the most important invention of Schmidt's lifetime, indeed an invention that revolutionized astronomy and optical design in the second half of the 20th century, namely his wide-angle reflective camera.
The Schmidt Camera
Astronomers had long wished for a way to photograph large swathes of the sky quickly for the purpose of surveying the visible contents of the universe and seeing large-scale structures. Ordinary telescopes up till Schmidt's time showed narrow fields of view, typically measuring 1 or 2 degrees in diameter. Surveying the whole sky with such telescopes required an enormous investment of time and resources over years and (because of the narrow views) tended to miss large structures. It was possible to see large swathes with small camera lenses, but then faint (and hence far away) objects would remain invisible. What was needed was large aperture cameras possessing wide fields of good imaging properties ("definition"), and fast focal ratios to decrease exposure times.Unfortunately, the only large aperture wide-field telescopes before Schmidt were ordinary reflecting telescopes of short focal ratio (about f/3), and these presented images which while sharp at the middle of their fields of view, quickly lost their definition away from the field center. Star images became bloated and comet-shaped, with the head of the "comet" pointing to the middle of the photographic field. This bloating results mainly from the optical aberrations (i.e. errors) called "coma" and "astigmatism." Before Schmidt it was impossible to build a large, fast reflector telescope which was not plagued by these errors.
Schmidt was well-aware of this and had been pondering possible solutions during the late 1920s. According to Baade, he had abandoned at least one solution already, when finally he hit upon his ultimate design, which involved a novel, indeed bold departure from traditional optical designs. Schmidt realized that by employing a large spherically shaped mirror (instead of the normal paraboloidal mirror of a reflector telescope) and a smaller apertured diaphragm placed at the center of curvature of the mirror, he could at a stroke eliminate coma and astigmatism. He would be left, however, with spherical aberration which is just as damaging to image sharpness.
His boldness lies in realizing that he could eliminate the spherical aberration by placing a thin, very weakly curved aspheric lens
Aspheric lens
An aspheric lens or asphere is a lens whose surface profiles are not portions of a sphere or cylinder. In photography, a lens assembly that includes an aspheric element is often called an aspherical lens....
(now called the "Schmidt corrector plate
Schmidt corrector plate
A Schmidt corrector plate is an aspheric lens which is designed to correct the spherical aberration in the spherical primary mirror it is combined with. It was invented by Bernhard Schmidt in 1931, although it may have been independently invented by Finnish astronomer Yrjö Väisälä in 1924...
") at the same center of curvature as the apertured diaphragm. This aspheric lens has a complex curve that is convex near its middle and concave near its periphery that creates the opposite spherical aberration of the spherical mirror it is paired with, canceling out the mirror's spherical aberration. In this way, very neatly and simply he could construct a large camera of f/1.75 or even faster, that would give sharp images across a field more than 15 degrees in diameter, making it possible to image large swathes of sky with short exposures (on the order of a few minutes versus an hour or more with a conventional reflector). His first camera had an aperture of about 360mm or 14.5" in diameter, and a focal ratio of f/1.75. It is now housed in a museum at the Hamburg Observatory. Schmidt's combining of diverse optical elements (a special mirror, a diaphragm at a particular location, and a "correction plate") into a simple catadioptric
Catadioptric
A catadioptric optical system is one where refraction and reflection are combined in an optical system, usually via lenses and curved mirrors . Catadioptric combinations are used in focusing systems such as search lights, headlamps, early lighthouse focusing systems, optical telescopes,...
system, based on reasoning from first principles, was epoch making. In particular, the "correction plate" was like nothing ever seen before in telescope design. After Schmidt a flood of new catadioptric designs appeared in the subsequent decades.
Last years
Schmidt built his first "Schmidtspiegel"(which came to be known as the Schmidt camera) in 1930, a breakthrough which caused a sensation around the world. He employed a very clever method (the so-called "vacuum pan" method) to make the difficult "corrector plate," so that the system gave superb images. The vacuum pan involved carefully warping a parallel glass plate under partial vacuum into a slight sagging curve and then polishing the upper curve flat. After release of the vacuum, the lens would spring back into the "Schmidt shape" needed for the camera. No one had ever made a lens in this way before.Schmidt published a brief account (in German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....
) of his invention in professional publications, and offered to build his cameras for professional observatories. Unfortunately, his publicity was too little and his design was too novel. Moreover, the invention coincided with the beginning of the Great Depression
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
. No orders came in and he remained dependent on Schorr and Bergedorf for a modest income from occasional jobs till the end of his life. He produced a larger camera in 1934 and reground the 60cm Bergedorf-Steinheil photographic refractor as well.
Schmidt fell ill at the end of November 1935 after a business trip to Leiden in the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
. Despite attempts at treatment, he died on December 1, 1935 at the age of 56. An autopsy
Autopsy
An autopsy—also known as a post-mortem examination, necropsy , autopsia cadaverum, or obduction—is a highly specialized surgical procedure that consists of a thorough examination of a corpse to determine the cause and manner of death and to evaluate any disease or injury that may be present...
revealed that he was suffering from a lung infection.
Personal life & legacy
Walter Baade
Wilhelm Heinrich Walter Baade was a German astronomer who worked in the USA from 1931 to 1959.-Biography:He took advantage of wartime blackout conditions during World War II, which reduced light pollution at Mount Wilson Observatory, to resolve stars in the center of the Andromeda galaxy for the...
when he arrived at the Mount Wilson Observatory
Mount Wilson Observatory
The Mount Wilson Observatory is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a 5,715 foot peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles...
in the United States, the Schmidt telescope idea took off. An 18" Schmidt was produced in 1938 and then ten years later, the famous 48" (122 cm) Samuel Oschin telescope
Samuel Oschin telescope
The Samuel Oschin telescope is a 48-inch aperture Schmidt camera at the Palomar Observatory in northern San Diego County, California. It consists of a 49.75-inch Schmidt corrector plate and a 72-inch mirror. The instrument is strictly a camera; there is no provision for an eyepiece to look...
Schmidt-telescope was built at Mount Palomar Observatory. This last telescope produced a flood of new observations and information. It proved the brilliance of the Schmidt concept beyond doubt.
Subsequently at Bergedorf in 1955 a large, well-constructed Schmidt was dedicated. The 2-meter Schmidt telescope of the Karl Schwarzschild Observatory
Karl Schwarzschild Observatory
The Karl-Schwarzschild-Observatorium is an astronomical observatory owned and operated by the institute of Thüringer Landessternwarte ’Karl Schwarzschild’ Tautenburg. In 1992 it was acquired by the state of Thuringia...
was built later and remains the largest Schmidt camera in the world, although more technologically advanced versions have since been produced. The Bergedorf Schmidt was moved to Calar Alto Observatory
Calar Alto Observatory
The Calar Alto Observatory is an astronomical observatory owned and operated jointly by the Max-Planck-Institut für Astronomie in Heidelberg, Germany, and the Instituto...
in 1976.
B. Schmidt is also the protagonist of the biographic novel Vastutuulelaev by Estonian author Jaan Kross
Jaan Kross
-Early life:Born in Tallinn, Estonia, studied Jacob Westholm´s Grammar school, Kross attended the University of Tartu and graduated from its School of Law...
.
External links
- Biography
- http://www.hs.uni-hamburg.de/EN/Oef/Stw/schmidt/schmidt.jpg The original Schmidt Telescope.
