The Gauss lens is a
compound
Compound may refer to:
Architecture and built environments
* Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall
** Compound (fortification), a version of the above fortified with defensive struct ...
achromatic lens
An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus on the same plane.
The most comm ...
that uses two uncemented
elements; in its most basic form, a positive
meniscus lens
A lens is a transmissive optical device which 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'') ...
on the object side and a negative meniscus lens on the image side. It was first proposed in 1817 by the mathematician
Carl Friedrich Gauss
Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes refer ...
for a
refracting telescope
A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens (optics), lens as its objective (optics), objective to form an image (also referred to a dioptrics, dioptric telescope). The refracting telescope d ...
design, but was seldom implemented and is better known as the basis for the
Double-Gauss lens
The double Gauss lens is a compound lens used mostly in camera lenses that reduces optical aberrations over a large focal plane.
Design
The double Gauss lens consists of two back-to-back Gauss lenses (a design with a positive meniscus lens on t ...
first proposed in 1888 by
Alvan Graham Clark
Alvan Graham Clark (July 10, 1832 – June 9, 1897) was an American astronomer and telescope-maker.
Biography
Alvan Graham Clark was born in Fall River, Massachusetts, the son of Alvan Clark, founder of Alvan Clark & Sons.
On January 31, 1862, ...
, which is a four-element, four-group compound lens that uses a symmetric pair of Gauss lenses.
Design
The
power
Power most often refers to:
* Power (physics), meaning "rate of doing work"
** Engine power, the power put out by an engine
** Electric power
* Power (social and political), the ability to influence people or events
** Abusive power
Power may a ...
of the positive element predominates, but the negative element corrects for
chromatic aberration
In optics, chromatic aberration (CA), also called chromatic distortion and spherochromatism, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the lens elements varies with the wave ...
; the positive element facing the object is made of
crown glass, while the negative element facing the image is made of
flint glass
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high Dispersion (optics), dispersion). Flint glasses are arbitrarily defined as having an Abbe number of 50 to 55 or less. The currently known flint gl ...
, separated by an air gap that takes the shape of a negative element. Gauss first described the arrangement in 1817.
Alvan Clark & Sons
Alvan Clark & Sons was an American maker of optics that became famous for crafting lenses for some of the largest refracting telescopes of the 19th and early 20th centuries. Founded in 1846 in Cambridgeport, Massachusetts, by Alvan Clark (1804&n ...
built a telescope for
Princeton University
Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...
in 1877 using a Gauss lens;
although Gauss had designed the optics to eliminate
spherical aberration
In optics, spherical aberration (SA) is a type of optical aberration, aberration found in optical systems that have elements with spherical surfaces. Lens (optics), Lenses and curved mirrors are prime examples, because this shape is easier to man ...
for different wavelengths, the Clarks "found these meniscus components difficult to make
nddisagreed that they gave a more complete achromatism and better definition". The telescope is now held by the
National Museum of American History
The National Museum of American History: Kenneth E. Behring Center collects, preserves, and displays the heritage of the United States in the areas of social, political, cultural, scientific, and military history. Among the items on display is t ...
.
Alvan G. Clark, the son of the founder of the eponymous American optical company, designed a photographic lens using a symmetric arrangement of two Gauss lenses and patented it in 1888;
introduced the
Zeiss Zeiss or Zeiß may refer to:
People
*Carl Zeiss (1816–1888), German optician and entrepreneur
*Emil Zeiß (1833–1910), German Protestant minister and painter
Companies
*Carl Zeiss AG, German manufacturer of optics, industrial measurem ...
''Planar'' as an improved Double-Gauss using cemented doublets in the place of the inner negative meniscus elements,
[ and Horace William Lee of the Taylor, Taylor and Hobson Company completed the evolution by introducing asymmetry to the Double-Gauss design with the 1920 ''Opic''.][ Derivatives of the ''Opic'' have dominated the design of high-speed (large aperture) photographic lenses since then.][
]
References
External links
*
Lenses
{{optics-stub