Ludwig Bertele

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Ludwig Jakob Bertele (* December 25, 1900 in Munich, Germany; † November 16, 1985) was an optical engineer and lens designer. He designed famous lenses like the Ernostar and the Sonnar.
Ludwig Bertele served as an apprentice at Rodenstock in Munich. After World War I he followed Prof. Dr. Paul Klughardt to the Heinrich Ernemann AG in Dresden. There Bertele designed a new, fast lens lens for projection; Alexander Ernemann pointed out, that this lens could be interesting also for cameras, so the Ernostar arose. First the 1:2/10cm (1923), then the 1:1,8/8.5cm (1924). This lens allowed to take pictures of moving subjects indoor without a flash light, so, for example, a new kind of stage photography was possible.
In 1929 Bertele took a time-out for three month, he used the time to visit the USA. When he went back to the Zeiss Ikon AG, which was his employer since several companies including Ernemann were merged in 1927, he hold the patent for a new lens, the Sonnar. At that time Zeiss Ikon took much effort to develop a camera for 35 mm film, the Contax, as a competitor to the Leica. The Sonnar outperformed the Biotar lens by Willy Merté, so it was chosen as standard lens for the Contax. Bertele designed several Sonnar lenses, standard lenses and telephoto lenses. The impressive 1:2.8/180 mm gained fame for its pictures from the Olympic games in Berlin 1936, so it was called Olympia-Sonnar. The wide-angle lens 1:3.5/35 mm Biogon completed the set of lenses.
In 1940 Bertele broke with Zeiss Ikon and changed to Steinheil in Munich, but before he could move his new dwelling in Munich was already destroyed by a bombardment, so he decided to stay in Dresden at this time. For Steinheil he had to design optical equipment for the military. When Dresden was destroyed in 1945, he managed to escape to Munich with his family.
After the war Ludwig Bertele moved to Switzerland, the Wild AG in Heerbrugg became his new employer. Wild, an supplier for geodetics, wanted to opt in to aerial photogrammetry. Berteles new task was to design the required lenses, so a set of three lenses was developed: the Aviotar (picture angle 60°), the Aviogon (90°) and the Super Aviogon (120°). Bertele was permitted to work for other companies besides his job at Wild. So he contrived a new Biogon based on the Aviogon, which was manufactured by Zeiss for the Contax, for Hasselblad and Linhof. In Addition, he helped Albert Schacht to design low-budget lenses for his company in Munich, later Ulm. After a controversy in 1956 Bertele worked as a freelancer for Wild until 1973.

Besides patents for lenses for photography Bertele was the holder of numerous patents on other sectors of optics, especially for a wide-angle eyepiece, useable for binoculars or microscopes.

In 1932 Ludwig Bertele married Erika Hemmann, they became parents of two sons. In his spare time he was interested in climbing, and he was the owner of a Harley-Davidson motorcycle, later with sidecar. He received numerous awards, in 1958 he became honorary doctor of the Swiss Federal Institute of Technology Zurich (ETH Zürich).

Important lenses

For the Ermanox camera:

  • Ernostar 1:2/10 cm and 1:1.8/8.5 cm

For the Contax camera:

  • Sonnar 1:1.5/50 mm, 1:2/50 mm, 1:2/85 mm, 1:4/135 mm and 1:2.8/180 mm (Olympia-Sonnar)
  • Biogon 1:3.5/35 mm

For aerial photography:

  • Aviotar
  • Aviogon
  • Super Aviogon


Erhard Bertele: "Ludwig J. Bertele, Ein Pionier der geometrischen Optik", vdf Hochschulverlag AG an der ETH Zürich 2017, ISBN 978-3-7281-3816-3


Bernd K. Otto: "Ludwig Bertele - auf den Spuren des Sonnars", detailed article in PhotoDeal 88, I/2015, in German


Dr. Ludwig Bertele at Zeiss Historica Society (archived)

Urs Tillmanns: book launch of the book of Erhard Bertele incl. short interview with the author at, in German