|with with Sonnar 7.5cm F4|
image by Kazutaka Tsutsui (Image rights)
|image by Romuald Swieconek (Image rights)|
|Carl Zeiss Jena Sonnar 4cm f/2 lens removed|
image by phollectormo (Image rights)
The Tenax II model 580/27 is an advanced 24×24mm on 35mm film RF-camera launched by Zeiss Ikon (ZI) in 1938. Its proper name is actually Tenax, but a much simpler camera with the same name, although with a different body casting, was launched the following year, both designed by Hubert Nerwin. The advanced 1938 model is known as mark II, or just Tenax II, while the simpler 1939 model 570/27, is known as Tenax I. The Tenax name goes back to the C. P. Goerz company in Berlin, using it from 1907 on folding plate cameras. It was used again by ZI in the 1960s. The manufacture of Tenax I was continued for a while in the 1950s in East Germany.
The main object of the Hubert Nerwin concept is speed, and both winding and focusing the camera, as well as setting the exposure, is exemplary quick and easy. This is accomplished using a large wind-lever at the right-hand camera front operated downwards by the index finger. It is mounted coaxially to the lensmount, and is sometimes described as a plunger. The shutter-release is just next to the top of the wind-lever in its rest position, enabling fast switching the finger back and forth.
The coupled rangefinder image is visible in the viewfinder. It employs two counter rotating sandwiched wedge-shaped prisms, placed in front of the rangefinder window. They are an integral part of the interchangeable lens, and therefore directly geared to the focusing mechanism in the lens barrel. This system is similar to that on the Super Ikonta, the Super Nettel and the Nettax, and it shows to what extreme ZI went to evade the Leica patents. The standard lens for Tenax II is the 1:2.8 f=40mm Tessar. A few extra lenses were also available.
The behind the lens shutter is a Compur Rapid OS leaf shutter speeded from 1 to 1/400 sec. and B. Time exposure is obtained at B by depressing the shutter release button and rotate it clockwise while depressed. The button is threaded for cable release. The square image format yields 48 images on a standard 36 image length of film.
The Tenax II was certainly inspired by the Robot camera, a small 24x24mm camera with spring-driven motorized film advance, launched in 1934. The format was indeed the same, as well as the emphasis on rapid action shooting. The rangefinder Tenax II was more sophisticated, but it was not commercially as successful, and production ended within a few years, unlike the Robot.
There are Tenax II cameras engraved Luftwaffeneingentum. A special version taking X-ray pictures, called the Röntgen-Tenax was also made available.
Tenax II lenses
The lens was interchangeable but only very few wide angle and tele lenses were produced. The very limited range of lenses was the following:
- Carl Zeiss Jena 4cm f/2 Sonnar standard lens
- Carl Zeiss Jena 4cm f/2.8 Tessar standard lens
- Carl Zeiss Jena 2.7cm f/4.5 Orthometar wide-angle lens
- Carl Zeiss Jena 7.5cm f/4 Sonnar tele lens
Tenax II accessories
- the close-up Contameter set, in a special version for the Tenax II, with code number 1339. It was sold in a case with a special close-up finder and three close-up lenses matched by three lenses for the finder device.
- accessory finder for the 2.7cm Orthometar
- finder mask for the 7.5cm Sonnar, #580/7
- Albada finder for 4cm and 7.5cm, #433/17
- Dechert, Peter. Tenax article 2006. Published in the Zeiss Historica Spring 2006 issue
|Zeiss Ikon Classic Cameras|
|Contax | Contaflex (TLR) | Super Nettel | Nettax | Tenax II | Tenax I | Ikoflex | Super Ikonta|