Engineering:Hologon

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Short description: Type of photographic recording lens
Hologon
Glatzel - Zeiss Hologon (1967).svg
Introduced in1966
AuthorErhard Glatzel
Construction3 elements in 3 groups
Apertureƒ/8

The Zeiss Hologon is an ultra wide-angle f=15mm f/8 triplet lens, providing a 110° angle of view for 35mm format cameras. The Hologon was originally fitted to a dedicated camera, the Zeiss Ikon Contarex Hologon in the late 1960s; as sales of that camera were poor and the Zeiss Ikon company itself was going bankrupt, an additional 225 lenses were made in Leica M mount and released for sale in 1972 as the only Zeiss-branded lenses for Leica rangefinders until the ZM line was released in 2005. The Hologon name was revived in 1994 for a recomputed f=16mm f/8 lens fitted to the Contax G series of rangefinder cameras.

Design

The Hologon was designed by Erhard Glatzel (de) and others at Zeiss in 1966[1][2] and patented in 1972. It is a largely symmetric triplet with a fixed aperture; the original German patent application describes a lens with 120° angle of coverage and a f/8 maximum aperture, while the US patent expands this to three related designs with different coverage angles and apertures (120° f/8, 110° f/5.6, and 90° f/8). In each design, the first and third hemispherical elements are made of optical glass with the same refractive index.[3] At least one prototype Hologon was built in 1964 or 1965 as a large-format lens with a focal length of 110 mm.[4] It has been shown via radiograph the large format Hologon 8/110mm uses a leaf shutter between the second and third elements, with adjustments to the first and third elements to accommodate it.[5] The prototype Hologon, internally known as the Bilagon, was sold at auction in 2010 for €28800.[6]

The name "Hologon" is derived from the Greek words holos, meaning "everything" or "complete", and gonia, meaning "angle"; gonia contributed the final syllable -gon, which had been used in preceding Zeiss wide-angle lens designs such as the Zeiss Distagon and Biogon.[2] As built, the symmetrical design for the Hologon 8/15mm by Glatzel provided excellent correction of coma, spherical and chromatic aberration, astigmatism, and curvature of field; the main fault was vignetting due to the cos4 law, which was corrected by supplying a graduated neutral density filter to make the exposure more even across the film frame.[5][7] Although the lens consists of only three elements, manufacturing proved difficult.[5]

Contarex Hologon ultra wide

The original Hologon (Contarex Hologon 8/15mm) was first released in 1969 as a f=15 mm f/8 lens affixed to a dedicated camera, the Zeiss Ikon Contarex Hologon. In this version, the lens is fixed focus and aperture; the size of the aperture is set by the incised notch in the second element.[5] Depth of field ranged from 0.5 m (20 in) to infinity.[8] A bubble level is fitted to the top of the (non-reflex) viewfinder.[9] Typically, a pistol grip is affixed to the Hologon camera to avoid inadvertently taking pictures of the photographer's fingers.[8][10]

Approximately 1,400 Contarex Hologon cameras were made;[7][10] production continued through 1975 in small batches.[5] In 1971, the list price for the Hologon was US$825 (equivalent to $5,208 in 2019), marked up from the wholesale cost of US$550 (equivalent to $3,472 in 2019).[11]

M Hologon 8/15mm

Hologon T* 16mm f/8 for Contax G, with finder, graduated filter, and case

The Contarex Hologon 8/15mm lens was later released as part of a set including a finder (with bubble level) and center graduated neutral density filter for Leica M cameras in 1972 (M Hologon 8/15mm). Estimates of production for the M Hologon 8/15mm range from 225 to 1,000.[12][13] The M Hologon 8/15mm gained a focusing helicoid compared to the Contarex Hologon 8/15mm, and could now be focused down to 0.2 m (7.9 in).[12][13] Because of the low production numbers and unique focal length, some lenses have been separated from the Contarex Hologon and adapted to Leica mount.[14]

G Hologon 8/16mm

Revised G Hologon 8/16mm layout

The G Hologon 8/16mm was announced with the Contax G1 in 1994;[15] the revised G Hologon 8/16mm retained the name from the earlier Contarex and M Hologon 8/15mm, but the construction was completely different, using 5 elements in 3 groups. Zeiss claimed that contrast had been improved by moving the rear element closer to the film plane. The new G Hologon 8/16mm was also provided with a graduated filter to provide a more even exposure.[16] The revised construction of the G Hologon 8/16mm also simplified assembly of the lens, as the cemented groups were easier to manufacture than the hemispherical front and rear elements of the Contarex and M Hologon 8/15mm.[2] Although nominally listed as a 16 mm lens, the focal length of the G Hologon 8/16mm is actually 16.5 mm and it provides coverage of 106° on the frame diagonal.[17] The G Hologon 8/16mm was the only lens for the Contax G that was manufactured in Germany.[18]

Like the earlier Contarex 8/15mm Hologon, the G Hologon 8/16mm also has been adapted unofficially to Leica M mount.[19]

References

  1. ↑ & Hans Schulz"Dreilinsiges Weitwinkelobjektiv [Three-lens wide-angle lens]" DE patent Application 1241637, issued 1 June 1967
  2. ↑ 2.0 2.1 2.2 Nasse, Dr. Hubert H. (December 2011). From the series of articles on lens names: Distagon, Biogon and Hologon (Report). Carl Zeiss AG. https://lenspire.zeiss.com/photo/app/uploads/2018/02/en_CLB41_Nasse_LensNames_Distagon.pdf. Retrieved 15 November 2018. 
  3. ↑ ; Hans Schulz & Ris Ruth et al."Three lens element wide angle objective" US patent Grant 3661447, issued 9 May 1972
  4. ↑ Foo, Leonard. "Carl Zeiss Designed 110mm 1:8 HOLOGON lens/compur shutter for LINHOF large format cameras - Part V". Malaysian Internet Resources. https://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/RF-Nikkor/Contax_RF/Zeiss-Hologon/index5.htm. Retrieved 15 November 2018. 
  5. ↑ 5.0 5.1 5.2 5.3 5.4 Cavina, Marco. "Hypergon - Topogon - Russar - Biogon - Aviogon - Hologon: La storia definitiva dei super-grandangolari simmetrici". http://www.marcocavina.com/articoli_fotografici/Hypergon_Topogon_Biogon_Hologon/00_pag.htm. Retrieved 8 November 2018. 
  6. ↑ Cröll, Arne (August 25, 2014). Large format lenses from Carl Zeiss Oberkochen 1950-1972 (Report). http://www.arnecroell.com/zeissoberkochen.pdf#page=32. Retrieved 15 November 2018. 
  7. ↑ 7.0 7.1 Foo, Leonard. "Zeiss Ikon/Voigtlander/Contarex Hologon (10.0659) Superwide Camera w/ 8/15 (15mm f/8.0) & other Hologon Ultra-wideangle lens variations - Part III". Malaysian Internet Resources. https://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/RF-Nikkor/Contax_RF/Zeiss-Hologon/index3.htm. Retrieved 15 November 2018. 
  8. ↑ 8.0 8.1 Elek, Mike (2018). "Zeiss Ikon Contarex Hologon". Classic Cameras. http://elekm.net/pages/cameras/contarex_hologon.htm. Retrieved 15 November 2018. 
  9. ↑ Foo, Leonard. "Zeiss Ikon/Voigtlander/Contarex Hologon (10.0659) Superwide Camera w/ 8/15 (15mm f/8.0) & other Hologon Ultra-wideangle lens variations - Part III". Malaysian Internet Resources. https://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/RF-Nikkor/Contax_RF/Zeiss-Hologon/index2.htm. Retrieved 15 November 2018. 
  10. ↑ 10.0 10.1 "Zeiss Ikon Contarex Hologon". Pacific Rim Camera. https://www.pacificrimcamera.com/pp/zicontrhol.htm. Retrieved 15 November 2018. 
  11. ↑ "Zeiss Ikon — Voigtländer Confidential Dealer Price Schedule". Pacific Rim Camera. February 15, 1971. https://www.pacificrimcamera.com/rl/01234/01234.pdf#page=2. Retrieved 15 November 2018. 
  12. ↑ 12.0 12.1 Bei, Jerry (March 14, 2018). "Zeiss Hologon 15mm F8 for Leica M". https://jerrybei.com/reviews/2018/3/14/zeiss-hologon-15mm-f8. Retrieved 15 November 2018. 
  13. ↑ 13.0 13.1 Foo, Leonard. "For LEICA M cameras - Part IV | Zeiss Ikon/Voigtlander/Contarex Carl Zeiss Hologon (10.0659) Superwide Camera w/ 8/15 (15mm f/8.0)". Malaysian Internet Resources. https://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/RF-Nikkor/Contax_RF/Zeiss-Hologon/index4.htm. Retrieved 15 November 2018. 
  14. ↑ Gandy, Stephen. "Adapted Zeiss 15/8 Hologon to Leica M Mount $2500". https://www.cameraquest.com/z_hologon.htm. Retrieved 15 November 2018. 
  15. ↑ "First Look: New Contax G1". Popular Photography: 26;30;186. November 1994. https://books.google.com/books?id=yUCq55hT0RoC&pg=PA22. Retrieved 15 November 2018. 
  16. ↑ "Carl Zeiss Hologon T* 16mm f8". Contax Cameras. https://www.contaxcameras.co.uk/_html/gseries/glenses/hologon16.html. Retrieved 15 November 2018. 
  17. ↑ "Hologon T* 8/16 datasheet". Carl Zeiss. https://www.zeiss.com/content/dam/camera-lenses/files/service/download-center/datasheets/historical-lenses/contax-g/datasheet-zeiss-hologon-816-en.pdf. Retrieved 15 November 2018. 
  18. ↑ "Contax G2 (brochure)". Kyocera Imaging. 1998. http://www.kyoceraimaging.com:80/docs/202000_brochure01.pdf. 
  19. ↑ Cavina, Marco. "Zeiss Contax Hologon 16mm f/8 su Leica IIIF BD a vite". http://www.marcocavina.com/adaptor/01_pag_holo16.htm. Retrieved 15 November 2018. 

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