Sony Launches FE 100-400mm F4.5 GM OSS

Sony Electronics has officially expanded its premium G Master lens lineup with the new FE 100-400mm F4.5 GM OSS, a super-telephoto zoom lens built for creators who need reach, speed, and mobility in one package. Designed for Sony Alpha full-frame E-mount cameras, the lens targets wildlife photographers, sports shooters, birding enthusiasts, and photojournalists who spend hours tracking fast-moving subjects. Because apparently chasing birds across wetlands at sunrise was not already difficult enough without carrying a lens the size of a small telescope.

The new lens introduces a constant F4.5 aperture across the entire 100-400mm zoom range, eliminating exposure shifts while zooming. Sony Electronics also claims autofocus performance up to three times faster compared to the previous FE 100-400mm F4.5-5.6 GM OSS, thanks to a new focus system powered by four XD Linear Motors and updated AF algorithms.

Constant F4.5 Aperture Across the Full Zoom Range

The standout feature of the new super-telephoto zoom is its constant F4.5 aperture. Unlike variable-aperture zoom lenses that darken as users zoom in, this lens maintains the same brightness throughout the entire focal range. That consistency is especially useful for sports and wildlife photographers working in unpredictable lighting conditions.

Sony’s optical design includes newly developed ED XA and XA elements, along with Super ED and ED glass components that help minimize chromatic aberration and maintain sharpness from edge to edge. Nano AR Coating II is also included to reduce flare and ghosting during backlit shooting situations.

Faster Autofocus for Sports and Wildlife

Sony Electronics is clearly aiming this lens at action-heavy photography. The upgraded autofocus system combines four custom XD Linear Motors with a floating focus mechanism for quicker subject acquisition and more stable tracking. Sony claims approximately 50 percent better subject tracking performance compared to the earlier model.

The lens is fully compatible with the Alpha 9 III’s continuous shooting capabilities, supporting burst rates up to 120 fps with AF/AE tracking. In practical use, that means photographers can capture split-second movements with greater consistency. Human beings have invented cameras capable of freezing a hummingbird wing at full speed, yet many still use them mostly for blurry food photos. Evolution is strange.

Built for Mobility and Handheld Shooting

Despite its long focal range and constant aperture, the FE 100-400mm F4.5 GM OSS weighs approximately 1,840 grams. Sony achieved this through a combination of magnesium alloy barrel components, lightweight optical engineering, and an internal zoom structure.

The internal zoom design keeps the lens length unchanged while zooming, helping maintain balance during handheld shooting. This is especially useful for sports sidelines, wildlife expeditions, or extended field sessions where constant repositioning is necessary.

The lens also supports optional 1.4x and 2x teleconverters, extending the focal length up to 800mm or even 1,200mm in APS-C mode. For bird photographers, that extra reach could make the difference between capturing detailed feather textures or just another distant dot in the sky.

Professional Controls and Video Features

Sony Electronics includes several professional-grade controls aimed at hybrid creators working across photography and video. The lens features built-in optical stabilization with Active Mode support, along with breathing compensation compatibility on supported Alpha camera bodies.

Additional controls include four customizable focus hold buttons and a dedicated function ring for personalized handling. The lens also features a dust and moisture resistant construction with a fluorine-coated front element designed for outdoor use in more demanding environments.

For creators who regularly shoot in rain, dust, or rough outdoor conditions, durability matters just as much as optical quality. Nobody enjoys explaining to their bank account why a lens worth over four thousand dollars stopped working because of a little mud and optimism.

With the launch of the FE 100-400mm F4.5 GM OSS, Sony Electronics continues to strengthen its high-end Alpha ecosystem for professional and enthusiast creators alike. The lens is scheduled to arrive in June 2026 with a retail price of approximately $4,299.99 USD in North America.