Biogon

Biogon is the brand name of Carl Zeiss for a series of photographic camera lenses, first introduced in 1934. Biogons are typically wide-angle lenses.

History

''Biogon'' (I), 1934

File:Bertele-Zeiss Biogon (1934).svg, Zeiss ''Biogon'' by Bertele (1934), from US 2,084,309
File:Bertele US2549159A (Aviotar, 1947).svg, Wild ''Aviotar'' by Bertele (1947), from US 2,549,159
File:Jupiter-12 (Contax-Kiev lens mount).JPG, KMZ ''Jupiter-12'' lens

The first ''Biogon'' lens (2.8 / 3.5 cm, an asymmetric design featuring seven elements in four groups) was designed in 1934 by Ludwig Bertele while he was working for Zeiss, as a modification of his earlier '' Sonnar'' design (1929). The ''Biogon'' was assigned to Zeiss Ikon Dresden and marketed with the Contax rangefinder camera. It was produced by Carl Zeiss starting in approximately 1937, first in Jena, then a redesigned version was built in Oberkochen.

Bertele would go on to reuse the design for the Wild ''Aviotar''. After World War II, KMZ also reused the ''Biogon'' design for the ''Jupiter-12''.

''Biogon'' (II), 1951

File:Tronnier US1882530A (Angulon, 1930).svg, Schneider ''Angulon'' by Tronnier (1930), from US 1,882,530
File:Richter-Zeiss Topogon (1933).svg, Zeiss '' Topogon'' by Richter (1933), from US 2,031,792
File:Roosinov (1946).svg, Roosinov (1946), from US 2,516,724
File:Bertele US2734424A (Aviogon, 1950).svg, Wild ''Aviogon'' by Bertele (1950), from US 2,734,424
File:Bertele-Zeiss Biogon (1951, f4.5).svg, Zeiss ''Biogon'' by Bertele (1951), from US 2,721,499

Symmetric wide-angle lenses with meniscus elements facing the object and image had been developed in the 1930s, including the Schneider Kreuznach ''Angulon'' (Tronnier, 1930) with two outer negative menisci, derived from the Goerz ''Dagor'' ( Emil von Höegh, 1892); and the Zeiss '' Topogon'' (Richter, 1933) with two outer positive menisci, derived from the Goerz ''Hypergon'' (1900). These concepts were combined in a symmetric super-wide angle lens design using mirrored inverted telephoto lenses, as patented by Roosinov in 1946.

In 1950, Bertele designed the Wild ''Aviogon'' as a similar highly-symmetric wide-angle lens with a large angular coverage. The following year, in 1951, Bertele designed a new ''Biogon'' with a 90° angle of view (Super Wide Angle). The ''Biogon'' has been characterized as a simpler ''Aviogon''. Compared to the ''Aviogon'', the ''Biogon'' removed a meniscus element and simplified the group ahead of the aperture.

The first regular production ''Biogon'' lenses were produced from 1954 as the 4.5 / 21 mm for Contax, in 1954, 4.5 / 38 mm for Hasselblad Super Wide, and from 1955 to 1956 as the 4.5 / 53 mm and 4.5 / 75 mm for Linhof. The original patent spanned three different variants, each with a different maximum aperture: 6.3, 4.5, and 3.4 lenses.

File:AEG Weitwinkelobjectiv (1932).svg, AEG ''Weitwinkelobjektiv'' (1932), from DRP 620,538
File:Merté-Zeiss Sphaerogon (1935, fig 1).svg, Zeiss ''Sphaerogon'' by Merté (1935), from US 2,126,126
File:Angénieux - Retrofocus (1950).svg, Angénieux ''Retrofocus'' (1950), from US 2,649,022
File:Bertele US2730016A (Biogon 120-deg, 1952).svg, "Wide-angle lens" by Bertele (1952), from US 2,730,016

The advent of the ''Biogon'' opened the way to more extreme wide-angle lenses. Bertele continued to develop his design, patenting an asymmetric wide-angle lens in 1952 that covered an astonishing 120° angle of view "and beyond, practically distortion free", by adding a strong negative meniscus front element to the ''Biogon'' design, showing influences from earlier fisheye lens designs, including the AEG ''Weitwinkelobjektiv'' (1932) and Zeiss ''Sphaerogon'' (1935, ), and the Angénieux retrofocus (1950).

Examples

Since their introduction, lenses branded Biogon are usually approximately symmetrical ("semi-symmetrical") wide-angle design with a usable angle of view of 90° or more. At 90° the focal length is approximately half as long as the format's diagonal.

Well known camera manufacturers like Hasselblad have or had Biogon derived lenses to offer.

Biogon 1:2,8 ''f'' = 21 mm
90° angle (PDF-File; 65 kB)

Biogon 1:4,5 ''f'' = 21 mm, T* Classic
90° angle (PDF-File; 282 kB)

Biogon 1:2,8 ''f'' = 25 mm
82° angle (PDF-File; 292 kB)

Biogon 1:2,8 ''f'' = 28 mm
75° angle (PDF-File; 182 kB)

Biogon 1:2,0 ''f'' = 35 mm
63° angle (PDF-File; 266 kB)

Biogon 1:4,5 ''f'' = 38 mm CFi
for Hasselblad (Medium Format; PDF-File; 166 kB)
* Biogon 1:4,5 ''f'' = 53 mm, image diameter of 115 mm, for professional cameras up to the 6 × 9 cm

Biogon 1:5,6 ''f'' = 60 mm
for Hasselblad (Medium Format, including the Apollo Moon mission, PDF file, 857 kB); PDF-File; 857 kB)
* Biogon 1:4,5 ''f'' = 75 mm, image diameter of 153 mm, 92° angle, for large-format professional cameras up to 4 × 5 inches

Influence

File:Klemt US2781695A (Super Angulon, 1954).svg, Schneider Kreuznach ''Super-Angulon'' by Klemt (1954), from US 2,781,695
File:Schneider-Kreuznach Super-Angulon 1-8-65 (7528585730).jpg, Schneider Kreuznach ''Super-Angulon'' 65 mm for Linhof cameras
File:Leica Super Angulon 21mm f-4 1959 (32170504403).jpg, Licensed ''Super-Angulon'' 21 mm for Leica thread mount rangefinders
File:Minolta W.ROKKOR-PI 21mm f4.5 (2).jpg, ''W.Rokkor-PI'' 21 mm for Minolta SR-mount SLRs
File:0555 Nikkor SW 65mm f4 (9121968965).jpg, ''Nikkor-SW'' 65 mm for large format cameras

Several companies developed and sold highly symmetric super-wide angle lenses similar to the ''Biogon'', including:
* '' Super-Angulon'', sold by Schneider Kreuznach for large format cameras and licensed by Leica Camera as a 21 mm lens for Leica screw mount rangefinder cameras and a later lens for both M rangefinder and R SLR mounts; an unrelated ''Super-Angulon-R'' 21 mm was introduced a few years later, using a retrofocus design, as the prior symmetric design required the mirror to be locked up.
* ''Grandagon'', sold by Rodenstock for large format cameras
* ''Nikkor-O'' 2.1 cm , sold by Nikon in both S rangefinder and F SLR mounts; with the Nikon F, the lens must be used with the mirror locked up. This was replaced for the SLRs by the ''Nikkor-UD'' 20 mm retrofocus lens. Nikon also sold the ''Nikkor-SW'' line of highly symmetric super-wide angle lenses for large format cameras.
* ''W.Rokkor-PI'' and ''W.Rokkor-QH'' 21 mm lenses, sold by Minolta in SR mount. These were succeeded by the ''W.Rokkor-NL'' retrofocus lens, which did not require mirror lock-up.
* ''Fujinon-SW'', a six-element, four-group design similar to the ''Super Angulon'' sold by Fujifilm for both its line of Fujica medium format rangefinder cameras (G690/BL, GM670, GSW6xx) and large format cameras; an improved version (8e/4g) for large format cameras with slightly greater coverage was sold as the ''Fujinon-SWD''.

Günter Klemt patented the ''Super-Angulon'' for Schneider in 1954, citing Roosinov's 1946 patent; neither the Wild or Zeiss patents by Bertele were cited; The ''Super Angulon'' design shares the same six-element, four-group construction with inner cemented doublets flanked by large negative meniscus elements with the Roosinov patent, diverging significantly from Bertele's ''Aviogon''/''Biogon'' designs. The ''Super-Angulon'' bears more similarities to the prior ''Angulon'', designed by Albrecht Tronnier for Schneider in 1930 as another highly symmetric wide-angle lens with two cemented triplets. A later 1957 patent by Klemt in collaboration with Karl Heinrich Macher, refining the ''Super Angulon'' design for Schneider, added citations to Bertele's patents.

Wild continued to refine the ''Aviogon'' and filed for a patent on a simplified design in 1952; that patent, in turn, was cited by Drs. Erhard Glatzel and Hans Schulz in their 1966 patent for the '' Hologon''.

See also

* Biotar
*Tessar
* Planar
* Sonnar
*
*
* Hologon

References

Bibliography

*

External links

Detailed article about the history of super wide-angle lenses, starting with Hypergon (Italian)

Biogon wide-angle lens article on olypedia.de (German)

Historical Data sheets of Zeiss lenses (German)

{{DEFAULTSORT:Biogon
Photographic lens designs
Zeiss lenses