Lens Lab
    Tamron SP 400 mm F/ 4.0 LD-IF Adaptall-2 Model 65B
    Tamron SP 400 mm F/ 4.0 LD-IF Adaptall-2 Model 65B

    Tamron SP 400 mm F/ 4.0 LD-IF Adaptall-2 Model 65B

    400mm · f/4

    Overview

    The Tamron SP 400mm f/4 LD-IF 65B is a rare, professional-grade manual-focus super-telephoto lens praised for sharpness even wide open. It uses two low-dispersion elements and internal focusing, offering compact, reasonably lightweight build. However, some note the Adaptall mount can have slight play, and build feels less solid than competitors. It suits photographers seeking a fast 400mm for long reach, especially with compatible 1.4x/2x teleconverters, but scarcity drives high prices.