The Tokina SZX 400mm f/8 MF for the Micro Four Thirds (M4/3) mount is an ultra-compact mirror telephoto lens, designed for wildlife, astronomy, and super-telephotography enthusiasts who prioritize extreme portability. Utilizing catadioptric technology, this lens provides an astonishing equivalent focal length of 800mm on the M4/3 system, while maintaining an exceptionally light and manageable body.4 The mirror optical construction results in a fixed aperture of f/8, featuring the unique donut-shaped bokeh effect characteristic of these optical designs.6 As a manual focus (MF) lens, it requires precise adjustment, which, supported by the focus peaking features of M4/3 camera bodies, allows for achieving extremely sharp images over long distances.7 The mechanical design is optimized for field use: the barrel is robust and features a built-in sliding lens hood, which helps minimize flare and protect the front element. The Tokina SZX 400mm represents a cost-effective and highly portable solution for those looking to explore long-range photography without the bulk and weight of traditional refractive telephoto lenses.