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The name Summicron is used by Leica to designate cameralenses that have a maximum aperture of f/2 after 1953 and to present day.
History
The name Summicron is derived from summus, latin word for maximum and kronos, the ancient Greek word for time. In the 1950s Leica bought Crown glass from Chance Brothers, an English company and used it to make the lenses.
Leica designed a number of f/2 lenses before the Summicron, such as the Summar and Summitar. New coating technologies available after World War II allowed for the creation of the Summicron lens. The first Summicron was an evolved Summitar collapsible 50mm with Lanthanum glass, and was launched in 1953. Generations before approximately 1960 were produced in M39 mount ("screw mount"), then made available in M-mount (Latch-on A42), R-mount, and C-mount.
Description
The Summicron lenses have a maximum f-number of f/2.
Market position
Faster Leica lenses are offered with the trade names Noctilux (or Nocticron) and Summilux. Summarit, Elmarit, and Elmar lenses are slower.