Lens Lab
    Tamron SP 17 mm f/ 3.5 Adaptall-2 model 51B
    Tamron SP 17 mm f/ 3.5 Adaptall-2 model 51B

    Tamron SP 17 mm f/ 3.5 Adaptall-2 model 51B

    17mm · f/3.5

    Overview

    The Tamron SP 17mm f/3.5 Adaptall-2 (model 51B) is a vintage ultra-wide full-frame prime introduced in 1979, notable for its exotic focal length at the time. Optically, it is considered 'middle of the road'—adequate for most but softer wide open compared to modern lenses. Build quality is excellent: solid, with a smooth, dampened focus ring and a 135° throw, plus the versatile Adaptall-2 mount system. Downsides include no front filter thread; instead, it has three built-in color filters (81B, 80B, Y2) that are largely obsolete for digital use. It suits full-frame shooters or those using focal reducers on APS-C/S35, and is priced higher than other vintage primes due to its rarity and full-frame coverage.