The 135/4 Sonnar was one of the few lenses to be carried through the entire life of the Contax system. It's design was also used for the Contaflex Twin Lens as well as the Contarex.
Initially available in black and nickel, the minimum aperture started out as f//32. Within the year this was changed to f/16. The lens was offered in chrome in 1935, in preparation for the Contax II and III. The minimum f/ stop was f/16, but later was changed to f/22.
The lens was produced in a three color finish in 1937/38 for the Luftwaffen. It was chrome and black, with a grey aperture ring. In 1938 lenses were produced for the German navy with MF numbers engraved on the side. Some of these were supplied with Contax outfits to German U-boats.
As brass and chrome became vital war supplies, the barrel was produced in chrome. Some lenses are hybrids of chrome over brass and aluminum construction. A few of the lenses were issued with lens coating in 1942.
After the war, the East Germans resumed production of the lens in an aluminum barrel, highly polished. A few were built in chrome over brass. At least one lens was finished in ivory finish as a test for releasing the Contax II from Jena in Ivory finish. Neither the camera, nor the lens went into serial production.
In 1950 the 135/4 Sonnar went into production in West Germany at Oberkochen. Later, the Zeiss-Opton was changed to simply Carl Zeiss.
Black and nickel 135/4 Sonnar
The 135/4 mounted on a Contax I, with folding 50 and 135 finder.
The postwar 135 on a Contax IIa with appropriate turret finder.