Full-Frame E-mount. As a part of the FE line of lenses, the FE 400mm f/2.8 GM OSS is designed for Sony full-frame cameras. It’s also fully compatible with APS-C cameras, on which it’ll provide a 600mm equivalent focal length.

Pro-Grade Super Telephoto Prime. The FE 400mm f/2.8 GM OSS is a far-reaching super telephoto prime that’s great for sports, wildlife, and nature photographers and videographers who are looking for some extra reach. The rounded eleven-blade diaphragm creates smooth bokeh when you’re using selective-focus techniques.

Five-Axis Image Stabilization. A five-axis Optical SteadyShot image-stabilization system minimizes the appearance of camera shake, giving you sharp images even when you’re shooting hand-held at lower shutter speeds. The SteadyShot system will work with select cameras’ built-in sensor-shift image stabilization for even more effective blur control.

XD Linear Motor Autofocus System. This improved internal focusing system provides fast, nearly silent, and highly accurate autofocus performance that’s great for still and video use. You get a video-optimized “power focusing” mode that focuses smoothly to a preset recall position, and a dedicated focus hold button and AF/MF switch help tailor focusing to your shooting needs. Finally, there’s a new function ring with Preset Focus and Function settings.

Advanced Optics. The FE 400mm f/2.8 GM OSS’s 17-group/23-element design includes one extra-low dispersion element and three fluorite elements to minimize chromatic aberrations, and to produce clear, high-contrast images. A Nano AR coating keeps flare and ghosting at bay while maintaining color fidelity.

G-Master Series Quality. The GM series is Sony’s premium lens offering. What sets it apart from other Sony lenses is an emphasis on an extremely high resolving power of fifty lines per mm, out-of-focus “bokeh” quality, and a robust, weather-sealed body.

Comparatively Lightweight. This lens weighs just 6.38 lbs.—light by super telephoto standards. Its weight is distributed toward the back, making it easier to pan and track subjects.

Teleconverter Compatible. The FE 400mm f/2.8 GM OSS is compatible with 1.4x and 2.0x teleconverters.