Sigma 100-400mm f/5-6.3 DG DN OS C (Contemporary) APS-C Autofocus Lens for Fujifilm X-Mount Review

The Sigma 100-400mm f/5-6.3 DG DN OS Contemporary is a telephoto zoom designed for APS-C mirrorless cameras, here adapted for Fujifilm X-mount. It delivers an equivalent focal range of roughly 150-600mm on crop sensors, making it a versatile option for wildlife, sports, and distance work without the bulk of a full-frame telephoto. The Contemporary designation places it in Sigma's lightweight, travel-friendly tier, and the DG DN line is purpose-built for mirrorless systems rather than adapted from DSLR glass.

At $848, it slots into the affordable end of the long-reach zoom category for Fujifilm shooters. The lens includes optical stabilization, a 67mm filter thread, and ships with a hood and protective cover. Its f/5-6.3 variable aperture is typical for budget telephoto zooms and keeps size and weight manageable, though low-light performance will be more limited than faster constant-aperture options. For Fujifilm X-mount users seeking serious reach without committing to a premium native telephoto, this lens offers a practical entry point.