Description
The Carl Zeiss Jena Triotar 135mm f/4 is a classic telephoto lens based on the simple but effective Cooke Triplet optical design (3 elements in 3 groups). Originally designed in the 1930s, versions were produced for many years for various camera mounts, most commonly Exakta bayonet or M42 screw mount. While not as highly corrected as Tessar or Sonnar designs, the Triotar can offer surprisingly good sharpness, especially stopped down, and often produces distinctive, sometimes ‘bubbly’, bokeh. The note ‘ΘΕΛΟΥΝΣ SERVICE BLUE DOT’ indicates it needs servicing.