The Sony FE 100-400mm F4.5 GM OSS is aimed squarely at photographers who need significant reach, fast responses and dependable tracking for wildlife, sport and action photography. Its constant f/4.5 aperture, internal zoom and upgraded autofocus system suggest Sony is targeting photographers who need speed and reliability without stepping into the size and weight of a huge super-telephoto prime.
From the briefing information alone, it feels like a very considered update to the original 100-400mm, with a stronger focus on handling, balance and autofocus performance for modern high-speed cameras.
The Sony FE 100-400mm F4.5 GM OSS is a full-frame telephoto zoom lens for Sony’s E-mount mirrorless cameras. It sits above the original Sony FE 100-400mm lens, which launched in 2017, and is designed for photographers shooting wildlife, birds, sport, photojournalism and distant action.
Its name tells us quite a lot. FE means it is designed for Sony’s full-frame E-mount cameras, GM means it is part of Sony’s G Master series and OSS stands for Optical SteadyShot, Sony’s in-lens stabilisation system.
Sony says the lens is built for situations involving unpredictable movement, long-distance subjects and fast action where photographers need quick response and reliable tracking. That makes it particularly appealing for wildlife photographers and anyone photographing fast-moving subjects that don’t stay still for very long.
The Sony FE 100-400mm F4.5 GM OSS price is £4,400 or €5,000. It’s expected to go on sale in June.
The headline feature of the Sony FE 100-400mm F4.5 GM OSS is its constant f/4.5 maximum aperture. That means, unlike with the existing FE 100-400mm F4.5-5.6 GM OSS, the exposure doesn’t change as you zoom from 100mm to 400mm, which is especially useful when shooting action or recording video.
Inside, the lens has an advanced optical design with 28 elements in 20 groups. These include two Super ED (Extra-low Dispersion) elements, three ED elements, one XA (Extreme Aspherical) element and one ED XA element. Sony says this combination is designed to suppress chromatic aberration while maintaining strong contrast and detail throughout the zoom range.
Sony has also used Nano AR II coating to reduce flare and ghosting, while a fluorine coating on the front element helps repel moisture and fingerprints.
The Sony FE 100-400mm F4.5 GM OSS features an 11-blade circular aperture for smooth, rounded bokeh, which should help wildlife and sports subjects stand out nicely from busy backgrounds.
In addition, the lens is compatible with Sony’s 1.4x and 2x teleconverters, extending the focal length up to 800mm with the 2x converter attached.
Sony has also focused heavily on autofocus performance. Four XD (Extreme Dynamic) Linear Motors drive the floating focus system and Sony claims the autofocusing is up to three times faster than the existing FE 100-400mm while tracking performance is improved by approximately 50%.
At 119.8mm in diameter and 328mm long, the Sony FE 100-400mm F4.5 GM OSS is a sizeable telephoto zoom, but its 1,840g weight is lighter than some comparable professional-level super-telephoto zooms.
For photographers carrying equipment for long periods, that reduction in weight could make a real difference, especially during wildlife walks, travel assignments or long sporting events.
One of the biggest handling updates is the internal zoom design. Unlike the existing Sony FE 100-400mm, the barrel does not extend while zooming, which keeps the balance more consistent and should make panning feel smoother and more predictable.
Sony has also added zoom torque adjustment, allowing photographers to choose between a lighter or firmer zoom action depending on their preference.
The control layout is clearly designed with regular action and wildlife shooting in mind. On the right side of the barrel, there are four focus hold buttons alongside a large zoom ring and a slimmer focus ring closer to the mount. The two rings have different textures, making them easier to distinguish by touch while shooting and looking in the viewfinder.
The lens also has a customisable function ring. By default, this controls focus, but it can also be set to switch between full-frame and APS-C shooting or used for preset focus control.
There are dedicated switches for AF/MF (autofocus/manual focus), full-time DMF (Direct Manual Focus), the AF range limiter and OSS (stabilisation) control. OSS Mode 3 is designed for erratically moving subjects and activates stabilisation when the shutter button is fully pressed.
Other useful touches include a rear drop-in filter slot, a fluorine-coated front element, dust and moisture resistance and a security slot for attaching anti-theft accessories. The tripod collar is fixed rather than removable and the foot is not Arca Swiss compatible.
Read Our Sony FE 100mm F2.8 Macro GM OSS Review
I have not yet had the chance to shoot properly with the Sony FE 100-400mm F4.5 GM OSS, so these are first impressions based on Sony’s briefing information rather than real-world testing. However, the specifications suggest Sony has designed this lens very much with high-speed action in mind.
The autofocus system sounds especially promising. Sony says the autofocusing is significantly faster and more responsive than the original FE 100-400mm, while the improved tracking should help when following birds in flight or fast-moving sports subjects.
The lens also supports continuous shooting at up to 120fps with compatible Sony cameras such as the Alpha 9 III, which also illustrates how Sony is positioning it for serious action photography.
Sony’s sample images and MTF charts also suggest very strong image quality throughout the zoom range – but that’s why they show them at briefings. The company is claiming excellent detail and contrast from the centre to the edges, even at 400mm, while the advanced coatings and specialised glass elements are designed to keep flare, ghosting and chromatic aberration under control.
I’ll be interested to see how the balance and handling feel in practice, especially during longer handheld sessions, because that often matters just as much as outright sharpness when using longer lenses.
The Sony FE 100-400mm F4.5 GM OSS looks like a very promising addition to Sony’s telephoto line-up. Rather than simply refreshing the original 100-400mm, Sony appears to have concentrated on the areas that matter most to wildlife and action photographers, namely autofocus speed, subject tracking and handling.
For SheClicks readers photographing wildlife, birds, sport or distant action, it could prove especially appealing thanks to its balance of reach, speed and mobility. The internal zoom design also feels like a genuinely useful upgrade for photographers who spend long periods shooting handheld or tracking moving subjects.
Of course, the £4,400 price means this is firmly aimed at serious enthusiasts and professional-level photographers, and I’ll reserve final judgement until I’ve spent proper hands-on time with the lens. Even so, based on the briefing information, the Sony FE 100-400mm F4.5 GM OSS already looks like a strong addition to Sony’s G Master range.
