Metrogon
Encyclopedia
Metrogon is a high resolution, low-distortion, extra-wide field (90 degree field of view
) photographic lens
design, popularized by Bausch and Lomb. Variations of this design are said to have been used extensively by the US military for use in aerial photography
on the T-11 camera .
The most common Metrogon lenses have a f number of 6.3 and a focal length
of 6 inches. The company name Bausch and Lomb and the US Patent
number 2031792 are prominently inscribed on the front of the lens barrel . However, the said US Patent is of a 4 element lens that belongs to one inventor named Robert Richter of Carl Zeiss AG, filed in 1934 . For this reason, it is said that the Metrogon is a US version of the popular and very similar (if not identical) Topogon
design by Carl Zeiss.
In 1943, Bausch and Lomb themselves filed a patent for a similar, f/6.3 lens design but with 5 elements, under the US patent number 2325275, showing less distortion than the lens in the Carl Zeiss patent . It is not certain whether Bausch and Lomb incorporated their own design instead of the Zeiss design when producing lenses under the Metrogon name later on. The Bausch and Lomb patent also compares the distortion of their design favorably to another 5 element lens (US patent number 2116264) which has a slightly wider maximum f-number of f/5.6 .
Field of view
The field of view is the extent of the observable world that is seen at any given moment....
) photographic lens
Photographic lens
A camera lens is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.While in principle a simple convex lens will suffice, in...
design, popularized by Bausch and Lomb. Variations of this design are said to have been used extensively by the US military for use in aerial photography
Aerial photography
Aerial photography is the taking of photographs of the ground from an elevated position. The term usually refers to images in which the camera is not supported by a ground-based structure. Cameras may be hand held or mounted, and photographs may be taken by a photographer, triggered remotely or...
on the T-11 camera .
The most common Metrogon lenses have a f number of 6.3 and a focal length
Focal length
The focal length of an optical system is a measure of how strongly the system converges or diverges light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus...
of 6 inches. The company name Bausch and Lomb and the US Patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
number 2031792 are prominently inscribed on the front of the lens barrel . However, the said US Patent is of a 4 element lens that belongs to one inventor named Robert Richter of Carl Zeiss AG, filed in 1934 . For this reason, it is said that the Metrogon is a US version of the popular and very similar (if not identical) Topogon
Topogon
Topogon is a wide field , symmetrical photographic lens designed by Robert Richter in 1934 for Zeiss Carl FA . Lenses produced under the name Metrogon also cite the US patent of the Topogon design....
design by Carl Zeiss.
In 1943, Bausch and Lomb themselves filed a patent for a similar, f/6.3 lens design but with 5 elements, under the US patent number 2325275, showing less distortion than the lens in the Carl Zeiss patent . It is not certain whether Bausch and Lomb incorporated their own design instead of the Zeiss design when producing lenses under the Metrogon name later on. The Bausch and Lomb patent also compares the distortion of their design favorably to another 5 element lens (US patent number 2116264) which has a slightly wider maximum f-number of f/5.6 .