Sony Electronics has introduced two G Master super-telephoto prime lenses for its Alpha full-frame E-mount system, the FE 400mm F4.5 GM OSS and the FE 600mm F6.3 GM OSS. The company describes them as the lightest lenses in their respective categories, a claim that stands up given each weighs under a kilogram.
The FE 400mm F4.5 GM OSS weighs approximately 994 grams and the FE 600mm F6.3 GM OSS weighs approximately 995 grams, a difference of just one gram between the two. This weight makes both lenses viable for active, handheld shooting styles that involve moving through an environment in search of a subject rather than working from a fixed position. Sony engineered the weight distribution so the center of gravity sits closer to the camera body and the tripod mount, rather than toward the front element. For anyone who has spent a day with a heavier super telephoto, this kind of rebalancing changes the experience noticeably. It becomes easier to hold a frame steady, track an erratic subject, or pan smoothly, and it reduces the fatigue that builds up during long handheld sessions photographing birds, wildlife, or sports.
Both lenses carry the resolution and bokeh characteristics associated with the G Master line across the super telephoto range. The optical formula for the FE 400mm F4.5 GM OSS uses 22 elements arranged across 16 groups, including three Super ED, or Extra low Dispersion, elements and one additional ED element. This kind of glass is specifically chosen to suppress the chromatic aberration and other optical flaws that tend to show up at long focal lengths, and the result is a lens that holds resolution well from the center of the frame out to the edges. Sony’s Nano AR Coating II is applied to reduce ghosting and flare in backlit conditions, a detail that matters more than it might seem for photographers who shoot into low morning or evening light. An 11 blade circular aperture, combined with careful optimization of spherical aberration during both design and manufacturing, produces the smooth, creamy out of focus rendering that G Master glass is known for.
Autofocus performance comes from two XD, or extreme dynamic, Linear Motors paired with a control algorithm tuned specifically for these two lenses. That combination is built for fast, precise, and quiet tracking of unpredictable subjects, and both lenses are fully compatible with the Alpha 9 III’s continuous shooting mode at up to 120 frames per second with AF and AE tracking. Built in optical image stabilization helps reduce camera shake at these focal lengths, and both lenses support a compatible camera body’s Active Mode stabilization and coordinated stabilization control, along with breathing compensation during movie recording to correct the shift in angle of view that can occur as focus changes.
In terms of physical dimensions, the FE 400mm F4.5 GM OSS measures approximately 108mm in maximum diameter and 242mm in length, while the FE 600mm F6.3 GM OSS shares the same 108mm diameter but extends to 263mm in length. According to early hands on reports, the only real physical difference between the two lenses is a longer section near the mount on the 600mm version, which accounts for both the extra length and the single gram of additional weight. Both lenses accept 95mm front filters and can focus as close as 2.5 meters. Because of the difference in focal length, though, their magnification differs: the FE 400mm F4.5 GM OSS reaches 0.18x maximum magnification, while the FE 600mm F6.3 GM OSS reaches 0.25x.
Control layout includes four customizable focus hold buttons positioned around the barrel, along with a function ring, a focus range limiter, a Full time DMF switch, a focus mode switch, and an image stabilization mode switch, giving photographers quick access to the adjustments they need without hunting through camera menus mid shoot. Sony’s optional teleconverters extend the reach of both lenses considerably. With a 1.4x teleconverter attached, the FE 400mm F4.5 GM OSS becomes an effective 560mm F6.3, and with Sony’s full teleconverter lineup, the 400mm lens can reach 800mm while the 600mm lens can reach up to 1200mm. Both lenses also feature a dust and moisture resistant build along with a fluorine coating on the front element, which helps repel water, dust, and fingerprints during outdoor use in less than ideal conditions.
Yang Cheng, Vice President of Imaging Solutions at Sony Electronics, said the goal was to apply the company’s G Master expertise for wildlife and sports photographers, from casual birders on a morning hike to professionals working the sideline, resulting in what Sony calls the lightest lenses in their class without sacrificing image quality or a design that stays comfortable to carry all day.
Positioned against the competition, the FE 400mm F4.5 GM OSS gives Sony shooters a direct answer to Nikon’s well regarded Nikkor Z 400mm f4.5 VR S, and Sony’s version is even lighter. It also becomes Sony’s first true alternative to the Sigma 500mm F5.6 DG DN Sports for photographers who prioritize a lightweight, carry all day prime. Both new primes also overlap with the focal range of Sony’s existing 400 to 800mm F6.3 to 8 G OSS zoom, though the primes trade zoom flexibility for a marginally brighter maximum aperture and a significant weight advantage.
Both lenses will be available starting in October 2026. The FE 400mm F4.5 GM OSS carries an MSRP of 2,699.99 USD and 3,579.99 CAD, and the FE 600mm F6.3 GM OSS carries an MSRP of 3,699.99 USD and 4,999.99 CAD.
