First Look: I Took Sony's New 100-400mm f/4.5 GM OSS to an MLS Match

Sony has officially announced the new FE 100-400mm f/4.5 GM OSS, a super-telephoto zoom designed for wildlife, birding, sports, and photojournalism work.

I recently had the good fortune of spending some time with the new lens on the sidelines of an MLS match, shooting the Seattle Sounders — and in my opinion, this is exactly the kind of constant-aperture, long-reach G Master zoom that Sony's professional sports and wildlife shooters have been waiting for. Let's take a look at what makes this lens such a compelling addition to the acclaimed lineup of Sony G Master lenses.

Key Features

• 100–400mm super-telephoto zoom range with a constant f/4.5 maximum aperture
• 20–28 elements including ED XA (extra-low dispersion extreme aspherical), XA, Super ED, and ED glass
• Nano AR Coating II for reduced flare and ghosting
• 11-blade circular aperture for smooth, refined G Master bokeh
• Four XD (Extreme Dynamic) Linear Motors with up to 3x faster autofocus and up to 50% improvement in subject tracking versus the previous model
• High-speed AF tracking at up to 120 frames per second during burst shooting
• Optical SteadyShot with multiple modes (Mode 2 / Mode 3) for static subjects, panning, and unpredictable motion
• Inner-zoom design with internal focusing and floating focusing groups
• 1.4x and 2.0x teleconverter compatibility, extending reach up to 800mm
• Minimum focus distance of 0.64–1.5m with a 0.25x maximum magnification
• Weight: 1,840 g (65 oz); 95mm front filter / 40.5mm drop-in filter
• Dust and moisture-resistant construction with fluorine coating on the front element

A New Optical Formula for the G Master Lineup

In typical Sony fashion, the FE 100-400mm f/4.5 GM OSS leans heavily on the optical advancements that have come to define recent additions to Sony's premium telephoto lineup. The 20–28 element formula combines ED XA, XA, Super ED, and ED glass to suppress chromatic aberration, spherical distortion, and field curvature across the entire 100–400mm range — which is no small feat in a constant-aperture super-telephoto zoom. The 11-blade circular aperture is engineered to produce the smooth, refined bokeh G Master lenses are known for, with reduced onion-ring artifacts that should be especially welcome at long focal lengths where subject separation is everything.

Just as importantly, the lens utilizes both an internal focusing mechanism and a floating focusing system. That means consistent image quality across varying focus distances and a center of gravity that doesn't shift as you rack focus.

On the Pitch: Shooting an MLS Match With the Seattle Sounders

For me, this is where the new 100–400mm really started to shine. Shooting sidelines at an MLS Sounders match is exactly the kind of run-and-gun environment a super-telephoto zoom has to handle — fast subject movement, constant focal length adjustments between near-side play and far-side goal action, and the relentless pressure to capture decisive moments without missing a beat.

Four XD Linear Motors deliver autofocus performance that Sony rates as up to 3x faster than the previous model, with a 50% improvement in subject tracking accuracy — and on the pitch, that improvement was immediately noticeable. The lens locked onto players quickly, held focus through fast direction changes, and stayed glued to subjects breaking toward goal. Paired with a Sony a9 III body, the lens can track at up to 120 frames per second during burst shooting, and that blazing-fast tracking made nailing keeper shots-on-goal incredibly easy.

The constant f/4.5 aperture also made a meaningful difference for me. Not having to manage exposure shifts as I zoomed in and out of the action kept my workflow consistent throughout the match, and the inner-zoom design kept the lens balanced and predictable in hand from the opening whistle to the final stoppage.

Inner-Zoom Build and Versatile Operability

At 1,840 g (roughly 65 oz), the FE 100-400mm f/4.5 GM OSS sits on the lighter end of the spectrum for what it offers, and the inner-zoom design keeps the lens balanced whether you're shooting handheld in run-and-gun situations or mounted on a tripod or monopod. Operability is where Sony's professional G Master lenses really shine, and this one is no exception: a customizable function ring, four focus hold buttons, an AF/MF focus mode switch, full-time DMF support, a focus range limiter, an OSS on/off switch, and an OSS Mode switch (Mode 2 / Mode 3) give you fine-grained control without ever needing to leave the eyepiece.

The lens also features a tripod collar with a ring-clicking select switch, a 40.5mm drop-in filter slot to complement the 95mm front filter thread, and full compatibility with Sony's 1.4x and 2.0x teleconverters — pushing the reach all the way out to 800mm while maintaining AF performance and image quality. Weather sealing, sealed seams, silicone rubber gaskets at the switches, and a fluorine-coated front element round out a build that's clearly purpose-built for working in less-than-ideal conditions.

Pricing and Availability

The Sony FE 100-400mm f/4.5 GM OSS is expected to retail at approximately $4,299 USD ($5,599 CAD), with availability beginning in early June.

Final Thoughts

After spending time with the new FE 100-400mm f/4.5 GM OSS on the sidelines of an MLS match, I can confidently say this lens is set to become a serious new workhorse in the G Master telephoto lineup. A constant f/4.5 aperture, a substantial improvement in autofocus and tracking over the previous model, an inner-zoom design that doesn't shift weight, and the kind of weather-sealed build you can take out into the field for an entire shoot day.

For me, this lens checks every box that working wildlife, sports, and photojournalism shooters care about. Sony Alpha shooters who demand reach, speed, and reliability in a single super-telephoto zoom should look no further than the new Sony FE 100-400mm f/4.5 GM OSS.

What's your take on Sony's new FE 100-400mm f/4.5 GM OSS? Share your thoughts in the comments below!