Sony 100 - 400 mm GM II & More - Is a Major Breakthrough Coming?
Sony’s Rumor Mill Is Working Overtime
Rumors are growing louder in the photography community: Sony appears to be reshaping its telephoto segment. At the center of it all is the popular but now aging 100–400 mm f/4.5–5.6 GM OSS.
Since its launch in 2017, the lens has built a reputation as a versatile all-rounder for sports and wildlife photography. But in the age of 120 fps cameras like the Sony A9 III, a simple refresh is no longer enough.
Several Lenses in Development?
Insider information and patent filings suggest that Sony is working on more than just one new telephoto lens - possibly several.
GM II: A Real Telephoto Update?
The long-awaited Sony 100 - 400 mm GM II is expected to feature faster and more precise motors to fully leverage the high-speed autofocus in Sony’s current flagship models. Weight is another key topic: the current GM comes in at almost 1.4 kilograms. The new version will reportedly aim for around 1,200 g.
Then there’s the rumor of a constant f/4.0 aperture. It sounds fantastic, but in this class, it would be a serious engineering challenge. A more realistic scenario is an optimized variable aperture paired with a more compact design and faster, more accurate focusing—but hey, no harm in dreaming.
G Version: Slim, Lightweight, and Travel-Friendly?
Another lens circulating in the rumor world is the Sony 100–400 mm G. Not part of the GM series, no premium price tag. Instead: small, lightweight, and likely equipped with an f/5.6 - 8.0 aperture.
Target audience? Among others, users of the A7C, A7C II, A7CR, or a6700 who don’t want 1.4 kilograms hanging off the front of their camera but still want to maintain solid reach. Less light, sure - but with a better travel weight and an attractive price point, Sony could appeal to a broad audience here.
Sony’s 400 mm Prime is Also Moving Forward
In addition to zooms, Sony seems to be working on a new 400 mm f/4 prime. The patents are public, and the concept makes sense. It would bridge the gap between the 300 mm f/2.8 and the expensive 400 mm f/2.8 GM.
Especially interesting for wildlife fans: combined with the 1.4x teleconverter, it becomes a handy 560 mm setup—without the weight of the truly heavy hitters.
Launch Timing: December 2 Is No Coincidence
Leaks frequently mention December 2, 2025 - the expected launch date of the new Sony Alpha 7V.
Sony traditionally uses major camera releases to showcase matching lenses on the same stage. So chances are pretty good that one of the new telephoto lenses will be introduced alongside it.
Release Timing: Update December 3, 2025
During yesterday’s presentation of the a7 V, there was no additional “wow moment” apart from the camera itself. None of the 400 mm lenses circulating in the rumor mill were announced. So we will have to wait and see whether Sony will deliver any high-performance telephoto surprises around the start of spring in the first quarter of 2026.
Still, there was one new lens yesterday: the new standard kit lens, the Sony SEL FE 28–70 mm F3.5–5.6 OSS II.
In the end, the a7 V appeared exactly as the “rumor birds” had been chirping in recent weeks. The technical specifications leave a strong impression, especially the partially stacked sensor, which was long overdue.
What Does This Mean for Us Wildlife Photographers?
Nothing is confirmed yet, but the direction is clear. Anyone planning to invest in new telephoto gear in 2026 might want to wait a bit longer - and mark December 2 on their calendar.
The 400 mm f/2.8 Prime Is Still a Beast
→ You can find more in my long-term review here
