|2.4/35, for electric variant of the M42 screw mount as|
used on the Praktica PLC 2/PLC 3, image by Mjuboy (Image rights)
|2.8/35,image by Latente 囧||4/25, image by stammi|
|Pentacon Six with|
Flektogon 4/50, image by mflenses
The Flektogon was the first wide angle lens of its kind with short focal length and long back focal length. It was introduced in 1950 by VEB Carl Zeiss Jena, the East German Zeiss optics plant. The first variant was the Flektogon 2.8/35 for 35mm SLRs. Later other 35mm variants were made: 4/25, the remarkable fast 2.4/35 and the first super-wide angle lens 4/20. Medium format variants were made for the Pentacon Six: 2.8/65 and 4/50.
Other lens makers like Carl Zeiss Oberkochen (West Germany) made similar leses like the Distagon. It's a rare case of an eastern product copied in the West. Production of the manual-focusing Flektogon ended in 1991 whilst the Distagons are still in the market. A new variant by Carl Zeiss is the autofocus Flektogon 1:3,5/35mm for the Rolleiflex 6008 AF.