Sony FE 400mm F4.5 GM OSS

The Sony FE 400mm F4.5 GM OSS is a super telephoto prime for full frame Sony E-mount cameras. Sony announced it in September 2026 together with the FE 600mm F6.3 GM OSS. According to Sony, it is the lightest lens in its class, defined as 400 mm lenses with a maximum aperture of F4.5 or faster, and it is built for handheld wildlife, bird and sports photography.

Optical design

The lens has 22 elements in 16 groups. Sony names three Super ED elements and one ED element to suppress chromatic aberration and deliver resolution from the center to the edges. Nano AR Coating II reduces ghosting and flare, and an 11 blade circular diaphragm together with controlled spherical aberration is meant to give the G Master bokeh. The aperture runs from F4.5 to F32. Minimum focus distance is 2.5 m and maximum magnification is 0.18x.

Autofocus and handling

Two XD linear motors and a dedicated control algorithm drive autofocus. Sony states that the lens is fully compatible with the 120 fps continuous shooting of the Alpha 9 III with AF/AE tracking. Optical stabilization is built in and supports the camera's Active Mode and coordinated stabilization. Four customizable focus hold buttons sit around the barrel, and Sony lists a function ring, a focus range limiter, a full-time DMF switch, a focus mode switch and a stabilization mode switch. Breathing compensation on compatible bodies is supported.

Build and size

The lens weighs about 994 g without the tripod mount, measures 108 mm in diameter and 242 mm in length and takes 95 mm filters. Sony says the weight distribution places the center of gravity closer to the camera body, which helps when tracking and panning. A dust and moisture resistant design and a fluorine coating on the front element are described, without a guarantee of full protection. With the SEL14TC and SEL20TC teleconverters the focal length reaches 560 mm and 800 mm.

Where it fits

The FE 400mm F2.8 GM OSS is brighter but far larger, and the FE 600mm F4 GM OSS is in a different class. For zooms, the FE 200-600mm F5.6-6.3 G OSS and the FE 400-800mm F6.3-8 G OSS cover more range at lower light levels. The FE 100-400mm F4.5 GM OSS adds a zoom range to the same F4.5 aperture but at 1,840 g. The new FE 600mm F6.3 GM OSS is the longer sibling with almost the same weight and size.

Pros and cons

Pros

• Very light for a 400 mm F4.5 lens, about 994 g
• Center of gravity near the camera body
• Built-in stabilization and fast dual XD motor AF
• Many handling controls, including four focus hold buttons

Cons

• Fixed focal length, no zoom
• Close focus is limited to 2.5 m
• G Master pricing tier

Verdict

The FE 400mm F4.5 GM OSS targets photographers who want a bright 400 mm prime that can be carried and used handheld all day. It offers less flexibility than a zoom but is considerably lighter than F2.8 alternatives.