Fresh whispers from the rumor mill point to Sony prepping a second-generation FE 100-400mm F4.5-5.6 GM OSS II, a timely refresh for one of the E-mount system’s most beloved super-tele zooms.
With the original lens dating back to April 2017, this update could land just in time for major sporting events like the upcoming Olympics, where reach and reliability shine.
As third-party alternatives from Sigma and Tamron crowd the mid-range telephoto space, a GM II version would reaffirm Sony’s premium edge for wildlife photographers, sports shooters, and videographers chasing distant action without lugging exotic primes.
Autofocus & Weight Upgrades
Drawing from patterns in Sony’s GM refreshes—such as the featherweight 70-200mm F2.8 GM OSS II—expect the new iteration to:
- Trim some grams for improved portability
- Ramp up autofocus precision, potentially via faster linear motors
- Enhance tracking performance on high-speed bodies like the A1 II or A9 III
The original’s Direct Drive SSM system already set a high bar for quiet, accurate performance. An upgrade could deliver even smoother operation, minimizing hunting in low-contrast scenarios—crucial for birders and sideline professionals.
Optical & Coating Refinements
Optical tweaks might include:
- Refined glass elements to further reduce flare
- Enhanced Nano AR coating, building on the first-gen’s low-light prowess
These refinements would address evolving demands from hybrid shooters while preserving the original’s strengths.
Build Quality and Handling Updates
The GM II is likely to retain its rugged, dust- and moisture-resistant magnesium alloy shell, with potential refinements for:
- Better balance on gimbals or monopods
- Improved Optical SteadyShot, syncing more effectively with in-body stabilization
- Reduced focus breathing during zooms, aligning with Sony’s hybrid video strategy
At the long end, compatibility with 1.4x and 2x teleconverters should remain, extending reach to 800mm while preserving GM optical quality. Early buzz hopes for improved edge performance when extended.
Strategic Fit in Sony’s Lineup
This move would plug a gap in Sony’s lineup, where the original 100-400mm has aged gracefully but now faces stiffer competition from lighter, sharper rivals—potentially launching alongside the A7M5 for a system-level refresh.
If it follows the 70-200 GM II’s playbook, the new lens could be more than a refresh—it could be transformative for mobile shooters.
- Landscape photographers may benefit from distortion corrections
- Action shooters could see gains in customizable controls, such as expanded focus hold buttons for quick mode switching
Key Specifications (Rumored)
| Feature | Details |
|---|---|
| Lens Mount | Sony E-mount |
| Format | Full-frame |
| Focal Length | 100-400mm |
| Maximum Aperture | F4.5-5.6 |
| Minimum Aperture | F32-40 |
| Optical Construction | Rumored refinements to 22 elements in 16 groups (1 Super ED, 2 ED) |
| Autofocus Type | Enhanced Direct Drive SSM (speculated faster linear motors) |
| Image Stabilization | Optical SteadyShot (OSS), improved sync with IBIS |
| Minimum Focus Distance | Approximately 0.98m |
| Maximum Magnification | 0.35x |
| Filter Thread | 77mm |
| Dimensions | Speculated slimmer than original (94 x 205mm) |
| Weight | Rumored lighter than original 1395g |
| Weather Sealing | Dust- and moisture-resistant |
Expected to hover around $2,500 based on the original’s pricing, with a potential announcement alongside the A7M5 in October or November 2025, according to blog posts and forum discussions.