Joseph Petzval; ; (6 January 1807 – 17 September 1891Wiener Zeitung, 23 September 1891, p. 11) was a mathematician, inventor, and physicist best known for his work in optics. He was born in the town of Szepesbéla in the Kingdom of Hungary (in German: Zipser Bela, now Spišská Belá in Slovakia).

Petzval studied and later lectured at the Institutum Geometricum (currently Budapest University of Technology and Economics) in Buda (today part of Budapest). He headed the Institute of Practical Geometry and Hydrology/Architecture between 1841 and 1848. Later in life, he accepted an appointment to a chair of mathematics at the University of Vienna. Petzval became a member of the Hungarian Academy of Sciences in 1873.

Petzval is considered to be one of the main founders of geometrical optics, modern photography and cinematography. Among his inventions are the Petzval portrait lens and opera glasses, both still in common use today. He is also credited with the discovery of the Laplace transform University of St Andrews website, Józeph Miksa Petzval and is also known for his extensive work on aberration in optical systems.

Early life In 1801, Joseph Petzval's father married the Zipser German Susanne Kreutzmann, who was born in Szepesbéla, Kingdom of Hungary, a daughter of the previous teacher at the same school in Szepesbéla. The couple brought up six children: Gustáv Adolf (1800–1803), who died prematurely; Nestor Aemilianus (1804–1806); Joseph Maximilián (1807 - 1891); Petrol Baltazár (1809–1889); and three daughters. In 1810, the family moved to Késmárk (in German: Käsmark, today Kežmarok, Slovakia) and in 1819 to Lőcse (in German: Leutschau, today Levoča, Slovakia).

The entire family shared an aptitude for technology. Joseph's father worked as a teacher at the evangelical school in Szepesbéla, as well as an organist in Szepesbéla and later in Késmárk. He was also a conductor and a geodesist in Lőcse. He had a reputation as an outstanding musician and composer, who was also gifted mechanically. In 1824, he was awarded two patents: one for improvements to the pendulum clock and the other for a "polygraph" (typewriter). Petzval's brother, Petrol Baltazár Petzval, was a well-respected mathematician, engineer and astronomer.

Education

Joseph Petzval attended elementary school in Késmárk, and began his secondary school studies in Késmárk and Podolin (in German: Pudlein, now Podolínec, Slovakia). On 1 October 1819 he returned to his family in Lőcse, and entered high school. Both in elementary school and high school he ranked among the best in his class in the subjects of Latin (the official language of the Kingdom of Hungary) and religion; however, he struggled with his Hungarian. Before arriving at Lőcse, he was also very weak in mathematics. In Lőcse, however, he clearly improved in this discipline.

One anecdote told about Petzval is as follows: When his family had already decided to make a shoemaker out of Petzval, he read the book Analytic Paper on the Elements of Mathematics by the German mathematician Hauser over the summer holidays, just after completing his fourth class in elementary school. He was preparing to undergo a repeat class in mathematics. After Petzval finished the book, the child who had been a weak math pupil swiftly became a math genius.

After finishing high school, Petzval decided to move to the Institutum Geometricum, the engineering faculty of the Pester University. Before that, he had to complete a two-year lyceum, which he attended from 1823 to 1825 in Kassa (in German: Kaschau, today Košice, Slovakia). When he arrived there in 1823, Petzval was already well-versed in the subjects of Latin, mathematical analysis, classical literature and stylistics. In addition to his Slovak he was able to speak perfectly in Czech, German and Hungarian. With his father's assistance, he also learned French and English.

Further studies and career

After completing the Lyceum, Petzval worked for a year as an educator for Count Almássy in the Heves county. In addition to bringing in some urgently needed money, this experience also provided him with important social contacts.

From 1826 to 1828, Petzval studied at the Institutum Geometricum in Buda, and earned an engineering diploma in 1828. In the same year, he joined the graduate degree program of the university, and became the self-appointed adjunct chair for the Physics Department (in 1831). From 1828 to 1835, Petzval simultaneously worked as an urban engineer for the city of Buda—particularly as a specialist in flood abatement and sewers—and studied mathematics, mechanics and practical geometry. He authored an unrealized plan to build a navigation channel around Buda. In 1830, his dam computations saved the city from an inundation caused by the flooding of the Danube. After he received his Ph.D. in 1832, he taught as an associate professor at the university. During this period, he also received a degree in mathematics. In 1835, he was appointed a university professor in higher mathematics.

After being invited to the University of Vienna in 1836, Petzval accepted a position of the chair of mathematics there in 1837, and worked until 1877 as a professor of mathematics. Apart from mathematics, he was also concerned with mechanics, ballistics, optics, and acoustics. His lectures on the theory of algebraic equations, which integrated linear and differential equations with constant and variable coefficients, ballistics, acoustic theory, and other areas were high quality and became well attended.

Petzval moved into a rented abandoned monastery at Kahlenberg mountain. He founded his own glass-sharpening workshop there. His lenses became world-famous because Petzval was also a skillful lens sharpener and precision mechanic.

In 1840, he designed his famous portrait lens. 1845 brought disputes with the entrepreneur Peter Wilhelm Friedrich von Voigtländer (1812–1878) over who had the right to produce Petzval's lenses. In 1859, Petzval's home was broken into, and his manuscripts — a result of many years of research — were destroyed. Petzval never managed to reconstruct the lost documents. His most refined technical book on optics, lost with his manuscripts, would never appear in print. From then on, he primarily concerned himself with acoustics and began to withdraw from society. His enterprise with Carl Dietzler failed in 1862 (see further below); Dietzler died in 1872.

In 1869, at the age of 62, Petzval married his housekeeper, but she died four years later. In 1877, he stopped lecturing, withdrew to a monastery on Kahlenberg, and became a hermit.

Petzval died in Vienna in 1891, nearly forgotten, embittered, and destitute. His grave is in the Viennese central cemetery. His bitterness at the end of his life can probably be traced, on the one hand, to his continuing controversy with Voigtländer, the loss of his manuscripts, and his business failure; and on the other hand, to the fact that he was never really acknowledged for his lifelong work in the field of optics. Just before his death, Petzval was reported to have said:

"I defeated the light, I have it firmly in hand, because there is much darkness in the world too."

Private life and hobbies Petzval was a sportsman and a rider. As a young child, he often traveled with his family to the High Tatras. He was a recognized fencer and ring fighter in the city of Vienna. He inherited a talent for music from his father. Allegedly, while he was a lecturer in Vienna, he always rode to his lectures on a black Arabian horse.

Petzval did not share a lot about his private life, and was therefore relatively inscrutable to others during his lifetime. Dr. Ermenyi described in his book, Dr. Josef Petzval's Life

". . . he went so far as to always insert a bare point, for example, use the appearing annual yearbook of the Imperial Academy of Sciences, in whatever apart from the names of the members the date and the place appear aforementioned to the birth for itself into this column."

At the end of his life he lived in increasingly greater isolation in his "castle" on Kahlenberg, with only his horse for company, although several academies and scholarly societies appointed him a member (member of the Academy of Sciences in Vienna (1846/1849), external member of the Hungarian Academy of Sciences (1873), honorary member of the Union of the Czech mathematicians and physicists (1881), carriers of the French Charles Chevalier Platinmedaille, and others).

Disputes Petzval placed very high requirements on himself and others. That was probably connected with his critical, contentious and sarcastic nature, which brought him many conflicts, particularly in the field of mathematics.

Petzval had a controversy with Christian Doppler over problems of acoustics, and Doppler responded in 1852 with a book entitled "Remarks Over the Objections Stated by Professor Petzval Against the Correctness of My Theory".

In particular he was involved in lengthy disputes with the entrepreneur Voigtländer. These began in 1845, when Petzval raised the issue of fraud for the first time. Because Petzval only held a patent in Austria, Voigtländer shifted his production to Braunschweig in Germany, where he produced about 60,000 Petzval lenses in the following 20 years. Petzval for his part co-operated since 1854 with the Austrian optics producer Dietzler. The latter's lenses were marketed in Austria as the "photographic Dialyt", while Voigtländer marketed the lenses in Germany and Austria as the "Voightländer Orthoskop". After further interference by Voigtländer, Dietzler went bankrupt in 1862. When Petzval threatened legal action, Voigtländer closed his Austrian plant in 1866. Petzval could have then transferred the marketing, but he had renounced working with optics after his home was robbed in 1859 and worked instead on acoustics. In 1862, he also stopped lecturing on optics.

Discoveries and inventions

Optics

Petzval's greatest achievements lie in his work with geometric optics. In 1839, Louis Daguerre presented the Daguerreotype, the first commercially successful photographic process. Fox Talbot's calotype was discovered earlier but did not enjoy commercial success. Petzval learned of the invention from his friend, Viennese professor Andreas von Ettingshausen. The daguerreotype was problematic in that it required exposure times as long as 30 minutes to create a portrait. With Ettingshausen's urging, Petzval set up a workshop and laboratory at Kahlenberg in Vienna and, after six months of complex computations, produced designs for improved objective lenses for both portraiture and landscape photography. Because the artillery was one of the few occupations that used advanced mathematical computations at the time, Archduke Ludwig lent eight artillery cannoneers and three corporals to the computational efforts. The calculations these men carried out in tandem with each other have been regarded as an early (albeit human) example of a parallel computer.

Petzval's portrait objective lens (Petzval Porträtobjektiv) was an almost distortionless Anachromatischer vierlinser (double achromatic objective lens, with four lenses in three groups). The luminous intensity of this flat "portrait lens" was substantially higher than the daguerre standard of 1839, the Wollaston Chevalier lens (). The screen with a focal length of 160 mm made crucially shorter exposure times possible — using exposures of only about 15 to 30 seconds compared to the 10 minutes previously. Thus, snapshots became possible for the first time.