Sony FE 100-400mm F4.5 GM OSS Announced With Internal Zoom and Four XD Motors
Alongside the A7R VI, Sony has introduced the FE 100-400mm F4.5 GM OSS, a major update to its popular telephoto zoom. The new version delivers a constant F4.5 aperture across the entire zoom range, something Sony has never offered before in this focal length class. It also adopts a fully internal zoom design, which significantly improves handling and durability.
What changed
The original FE 100-400mm GM OSS from 2017 was well regarded, but its variable F4.5 to 5.6 aperture caused exposure shifts during zooming. The Mark II eliminates that issue with a constant F4.5 aperture. This provides more stable exposure for video and gives a slight brightness advantage at the long end.
The new lens also moves to an internal zoom mechanism. The barrel no longer extends while zooming. This improves balance on gimbals, reduces the amount of air drawn into the lens, enhances weather resistance, and gives the lens a more premium feel during operation.
Autofocus
Sony has equipped the 100-400mm GM with four XD Linear Motors in a dual drive floating focus system. This is the same autofocus motor architecture used in Sony’s flagship super telephoto primes. Sony states that autofocus speed is approximately three times faster than the previous generation and subject tracking performance is improved by about fifty percent. The lens is fully capable of keeping up with the A9 III during 120 frame per second continuous shooting.
Optical design
The optical system has been redesigned. It now uses 28 elements in 20 groups. This includes one ED XA element, one XA element, two Super ED elements, and three ED elements. All elements are treated with Sony’s Nano AR Coating II. The new design improves contrast, suppresses chromatic aberration, and maintains high resolution across the frame. Sony also reports improved close focus performance compared to the original lens.
Compatibility
The lens features Optical SteadyShot image stabilization. When combined with in body stabilization, it provides up to 5.5 stops of correction. It supports Sony’s 1.4x and 2.0x teleconverters. With the 1.4x converter, the lens becomes a 140 to 560mm F6.3. With the 2.0x converter, it becomes a 200 to 800mm F9. A focus range limiter is included to speed up autofocus in predictable shooting situations.
Key Specifications
| Feature | Details |
|---|---|
| Lens Mount | Sony E mount |
| Format | Full Frame |
| Focal Length | 100 to 400mm |
| Aperture | Constant F4.5 |
| Zoom Mechanism | Internal zoom |
| Autofocus | Four XD Linear Motors with dual drive floating focus |
| Minimum Focus Distance | 0.64 m |
| Image Stabilization | OSS plus IBIS, up to 5.5 stops |
| Optical Design | 28 elements in 20 groups |
| Special Elements | One ED XA, one XA, two Super ED, three ED |
| Teleconverter Compatible | 1.4x and 2.0x |
| Focus Range Limiter | Yes |
| Filter Thread | 95 mm front, 40.5 mm drop in |
| Weight | 1,840 g |
| Dimensions | 328 mm length, 120 mm diameter |
| Weather Sealing | Professional grade |
| Price | 4,299.99 USD |
| Availability | Late May 2026 |
Pricing and availability
The FE 100-400mm F4.5 GM OSS is available for preorder at 4,299.99 USD. The price is significantly higher than the original model at launch, but the upgrades place the Mark II in a different performance category. Shipments begin in late May 2026 alongside the A7R VI.