|
History Of Photographic Lens Design
The invention of the camera in the early 19th century led to an array of lens designs intended for photography. The problems of photographic lens design, creating a lens for a task that would cover a large, flat image plane, were well known even before the invention of photography due to the development of lenses to work with the focal plane of the camera obscura. Early photographic camera lenses (1800–1890) The early photographic experiments of Thomas Wedgwood, Nicéphore Niépce, Henry Fox Talbot, and Louis Daguerre all used simple single-element convex lenses. These lenses were found lacking. Simple lenses could not focus an image over a large flat film plane (field curvature) and suffered from other optical aberrations. Their severe longitudinal chromatic aberration meant the light the photographers were seeing (generally yellow light) and the light to which the early photographic mediums were sensitive not converge to the same point, making it difficult to focus. Charl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Petzval02
Joseph Petzval (6 January 1807 – 17 September 1891) was a mathematician, inventor, and physicist best known for his work in optics. He was born in the town of Spišská Belá, 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 lens, Petzval portrait lens and opera glasses, both still in common use today. He is also credited with the discovery of the Laplace transform and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Flint Glass
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). Flint glasses are arbitrarily defined as having an Abbe number of 50 to 55 or less. The currently known flint glasses have refractive indices ranging between 1.45 and 2.00. Traditionally, flint glasses were lead glasses containing around 4–60% lead(II) oxide; however, the manufacture and disposal of these glasses were sources of pollution. In many modern flint glasses, lead oxides are replaced with other metal oxides such as titanium dioxide and zirconium dioxide without significantly altering the optical properties of the glass. Applications A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects). History With respect to glass, the term ''flint'' derives from the flint nodules found in the ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hugo Adolph Steinheil
Hugo or HUGO may refer to: Arts and entertainment * Hugo (film), ''Hugo'' (film), a 2011 film directed by Martin Scorsese * Hugo Award, a science fiction and fantasy award named after Hugo Gernsback * Hugo (franchise), a children's media franchise based on a troll ** Hugo (game show) , ''Hugo'' (game show), a television show that first ran from 1990 to 1995 ** Hugo (video game) , ''Hugo'' (video game), several video games released between 1991 and 2000 * Hugo (album), a 2022 album by Loyle Carner People and fictional characters * Victor Hugo, a French poet, novelist, and dramatist of the Romantic movement. * Hugo (name), including lists of people with Hugo as a given name or surname, as well as fictional characters * Hugo Cabral (born 1988), Brazilian footballer * Hugo Chávez, president of Venezuela 1999-2013 * Hugo Gernsback, Luxembourgish American publisher (born 1884) * Hugo (musician), Thai American actor and singer-songwriter Chula Chak Charbonnages (born 1981) * Hugo (footba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Philipp Ludwig Von Seidel
Philipp Ludwig von Seidel (; 24 October 1821 in Zweibrücken, Germany – 13 August 1896 in Munich, German Empire) was a German mathematician. He was the son of Julie Reinhold and Justus Christian Felix Seidel. Philosopher & math theorist Imre Lakatos credits von Seidel with discovering, in 1847, the crucial analytic concept of uniform convergence, while analyzing an incorrect proof put forth earlier by Augustin-Louis Cauchy. In 1857, von Seidel contributed to the field of optics when he decomposed the first order monochromatic Aberration in optical systems, aberrations into five constituent aberrations. They are now commonly referred to as Optical telescope#The five Seidel aberrations, the five Seidel Aberrations. The lunar crater Seidel (crater), Seidel is named after him. His doctoral students include Eduard Study and Hermann Wiener. The Gauss–Seidel method is a useful numerical iterative method for solving linear systems. See also *Seidel triangle References Exter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Collodion Process
The collodion process is an early photography, photographic process for the production of grayscale images. The collodion process – mostly synonymized with the term "''wet-plate process''", requires the photographic material to be coated, sensitized, exposed, and developed within the span of about fifteen minutes, necessitating a portable darkroom for use in the field. Collodion is normally used in its wet form, but it can also be used in its dry form, at the cost of greatly increased exposure time. The increased exposure time made the dry form unsuitable for the usual portraiture work of most professional photographers of the 19th century. The use of the dry form was mostly confined to landscape photography and other special applications where exposure times sometimes longer than a half hour were tolerable. History Gustave Le Gray first theorized about the collodion process, publishing a method in 1850 that was "theoretical at best", but Frederick Scott Archer was credited wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Human Computer
The term "computer", in use from the early 17th century (the first known written reference dates from 1613), meant "one who computes": a person performing mathematical calculations, before electronic calculators became available. Alan Turing described the "human computer" as someone who is "supposed to be following fixed rules; he has no authority to deviate from them in any detail." Teams of people, often women from the late nineteenth century onwards, were used to undertake long and often tedious calculations; the work was divided so that this could be done in parallel. The same calculations were frequently performed independently by separate teams to check the correctness of the results. Since the end of the 20th century, the term "human computer" has also been applied to individuals with prodigious powers of mental arithmetic, also known as mental calculators. Origins in sciences Astronomers in Renaissance times used that term about as often as they called themselves " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Joseph Petzval
Joseph Petzval (6 January 1807 – 17 September 1891) 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 lens, Petzval portrait lens and opera glasses, both still in common use today. He is also credited with the discovery of the Laplace transform and is also known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Daguerreotype
Daguerreotype was the first publicly available photography, photographic process, widely used during the 1840s and 1850s. "Daguerreotype" also refers to an image created through this process. Invented by Louis Daguerre and introduced worldwide in 1839, the daguerreotype was almost completely superseded by 1856 with new, less expensive processes, such as ambrotype (collodion process), that yield more readily viewable images. There has been a revival of the daguerreotype since the late 20th century by a small number of photographers interested in making artistic use of early photographic processes. To make the image, a daguerreotypist polished a sheet of Plating#Silver plating, silver-plated copper to a mirror finish; treated it with fumes that made its surface light-sensitive; exposure (photography), exposed it in a camera obscura, camera for as long as was judged to be necessary, which could be as little as a few seconds for brightly sunlit subjects or much longer with less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Eyeglasses
Glasses, also known as eyeglasses (American English), spectacles (Commonwealth English), or colloquially as specs, are Visual perception, vision eyewear with clear or tinted lens (optics), lenses mounted in a frame that holds them in front of a person's Human eyes, eyes, typically utilizing a bridge over the nose and hinged arms, known as temples or temple pieces, that rest over the ears for support. Glasses are typically used for Corrective lens, vision correction, such as with reading glasses and glasses used for nearsightedness; however, without the specialized lenses, they are sometimes used for cosmetic purposes. Safety glasses are eye protection, a form of personal protective equipment (Personal protective equipment, PPE) that are worn by workers around their eyes for protection. Safety glasses act as a shield to protect the eyes from any type of foreign debris that may cause irritation or injury; these glasses may have protection on the sides of the eyes as well a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
