Update, September 15, 2026: The Sony FE 400mm f4.5 GM OSS is official
The rumor is a lens now. Sony announced the FE 400mm f4.5 GM OSS (SEL400F45GM) on September 15, 2026. Most of the leaked specs turned out to be right.
The lens weighs 994 grams without the tripod collar and measures 108 × 242 mm. Sony lists it at $2,699.99, and it ships from late September 2026. Even the price from the leaks, low as it looked at first, came close.
Two XD Linear Motors drive the autofocus. On the Alpha 9 III you get up to 120 frames per second, with autofocus and exposure keeping up through the burst. The teleconverters are confirmed too: the 1.4x TC gives you 560mm at f6.3, and the 2x TC 800mm at f9.
Weight, dimensions, the G Master name and the teleconverters all held up. The September 8 launch date that circulated first did not.
Update, September 13, 2026: According to the latest reports from SonyAlphaRumors, the Sony FE 400mm f4.5 GM OSS is supposed to be unveiled on September 15, 2026; so far, Sony has not officially confirmed it.
Update, September 9, 2026: Some of the rumors have been confirmed.
The Sony FE 8–14 mm f3.5 Fisheye G, which was named in the same round of rumors, has been officially unveiled. That confirms at least some of the speculation that had been circulating. The 400 mm f4.5 GM OSS, however, was neither announced nor mentioned in that release.
Judging by earlier rumors, though, that does not take the super-telephoto entirely off the table. An older tip had originally pointed to the second half of September for the unveiling. So, hope springs eternal, and the lens could still be officially announced in the coming weeks of September. On top of the lens not showing up, a supposedly leaked image of the Sony FE 400mm f4.5 GM OSS has now surfaced, and several rumor sites are currently picking it up.
As of September 7, 2026.
Sony has not officially confirmed a new prime lens, the FE 400mm f4.5 GM OSS.
Everything about this lens is a rumor from the past few weeks.
994 grams, 400mm at f4.5, and a price under $3,000. If the current rumors hold up, Sony would be launching a very light and affordable G Master super-telephoto for E-mount.
The numbers first showed up in the FredMiranda forum, and sites like SonyAlphaRumors, Photo Rumors, and Sony Addict picked them up. One thing matters here: these are not independent sources. All of the reports go back to the same information.
SonyAlphaRumors, citing its own source, reports that Sony will announce the lens on Tuesday, September 8, with preorders opening the same day.
At the time of writing, there is no official confirmation from Sony.
Sony usually sends newsletter subscribers a heads-up email before a new event.
Still, we can stay curious. The day is not over yet.
What is being reported about the Sony FE 400mm f4.5 GM OSS?
According to the leak, the lens is said to have these specs:
| Spec | |
|---|---|
| Focal length | 400mm |
| Maximum aperture | f4.5 |
| Weight | 994 g |
| Dimensions | 108 × 242 mm |
| Image stabilization | OSS |
| Price | $2,699–2,899 |
| Product line | G Master |
| Possible announcement | September 8, 2026, around 10:00 a.m. ET (4:00 p.m. in Germany) |
| Autofocus motors | unknown |
| Minimum focus distance | unknown |
| Filter size | unknown |
| Optical design | unknown |
994 grams would be a statement. If these rumors are true, Sony would land just under the 1 kilogram mark (about 2.2 pounds). For nature photographers, that would make this prime a very interesting option. You could pair it with the α7R VI (713 g) or the α6700 (493 g) for a light setup with plenty of crop reach. That matters most for those of us who walk a lot when we are out in the field. Less weight also helps when traveling, and it goes easy on the back for those of us who are not getting any younger.
Where do the rumors about the new Sony 400mm f4.5 GM OSS come from?
The first rumors did not start in September.
Back in March 2026, SonyAlphaRumors published an early hint that Sony was testing new 400mm and 600mm lenses that were much lighter than existing designs.
In August, leaks about 400mm f4.5 and 600mm f6.3 prototypes that Sony was said to be testing surfaced, without any concrete details.
Then, in September, a user in the FredMiranda forum finally posted technical data:
- 400mm f/4.5 GM OSS
- 994 g
- 108 × 242 mm
- $2,699 to $2,899
When asked, the user said the source was an authorized dealer, without naming names, of course.
SonyAlphaRumors, Photo Rumors, and Sony Addict then picked up these details as well.
That gives the rumor more reach, but for now it is no proof that we can count on this lens at all, let alone on a product launch on September 8, 2026.
Only on September 6 did SonyAlphaRumors add, by its own account, information from a second source that named September 8 as the launch date.
How much lighter would 994 grams be?
The most interesting part is the rumored weight of this E-mount lens.
Compared with the Nikon Z 400mm f4.5 VR S
Nikon’s directly comparable full-frame lens officially weighs 1,160 g without the tripod collar and measures about 104 × 234.5 mm.
If the rumored 994 g for the Sony 400mm holds up, the Sony would be:
- 166 g lighter
- slightly longer and wider
Nikon released the Z 400mm f4.5 VR S in 2022. Its current list price in the US is $3,249.95.
At $2,699 to $2,899, the Sony would come in roughly $350 to $550 below Nikon’s current 400mm f4.5.
Which of these claims are believable?
1. Is the price realistic?
$2,699 to $2,899 would be unusually low for a 400mm G Master.
Look at the price of the new 100–400mm f4.5 GM at $4,299.99, and it is hard to imagine this prime coming in even cheaper than the FE 400–800mm F6.3-8 G OSS. Sony’s existing G Master primes usually play in a different price league. So the price is the questionable part.
2. Is a 400mm f4.5 lens at this weight possible?
994 grams would be exceptionally light, but doable in principle, especially if the figure is without the tripod collar. Nikon’s 400mm f/4.5 comes in at 1,160 g, so Sony would need to shave off about 166 g. Depending on whether the weight is quoted with or without the tripod foot, that is generally achievable.
3. Will it be a G or a GM?
The current September rumors all name it GM OSS, even though the price would point more toward a G lens. Since the details largely trace back to the same original source, we will have to wait and see.
But G Master normally stands for the top tier of Sony lenses. If a 400mm comes in under 1 kg, you would also expect the latest technology in the focus motors and the glass, and that in turn does not sound like a G lens.
With the 300mm f2.8 GM, Sony has already shown how much weight modern optical and mechanical design can cut from professional telephoto lenses. It has also shown that this comes at a price.
What would 994 grams mean for wildlife photography?
This is where the rumor gets interesting for me personally.
My Sony 400mm f2.8 GM OSS weighs just under 2.9 kilograms (about 6.4 pounds). For its class, that is still “light” compared with the competition. But it is a lens where a tripod becomes a fixed part of the kit, especially on long days. I love this lens, but the weight is a big deal for me, especially when the hike to the spot where I want to sit and wait takes a while.
If you are willing to give up that much light, or if f4.5 is enough for you, a lens that is two-thirds lighter than the 400mm f2.8 is the way to go in my view.
A 400mm lens under one kilogram would be versatile, as long as it works well with the teleconverters.
| Combination | Focal length | Aperture | Weight lens + TC | Total weight with α7R VI |
|---|---|---|---|---|
| 400mm without TC | 400mm | f4.5 | 994 g | 1,707 g |
| with 1.4x TC (167 g) | 560mm | f6.3 | 1,161 g | 1,874 g |
| with 2x TC (207 g) | 800mm | f9 | 1,201 g | 1,914 g |
All three combinations with an α7R VI would still stay under 2 kg (about 4.4 pounds).
994 grams means less weight not only in your hands but also in your backpack, which matters when you travel by public transit or by plane. It also means much less strain on your body over a full-day outdoors. Those of us over 50, like me, know what I mean when I say that after a day with the gear, I feel it in my back the next morning.
If the rumors turn out to be true, this would be a very interesting lens for nature photography. Very light in the field, and with the latest technology to keep up with modern Sony cameras in focus and burst speed.
Frequently Asked Questions
When is the Sony FE 400mm f4.5 GM OSS supposed to be announced?
SonyAlphaRumors, citing its own source, reports a possible product launch on September 8, 2026. Sony has not officially confirmed anything so far.
How much is the Sony FE 400mm f4.5 GM OSS supposed to weigh?
The rumor puts the weight at 994 grams. That would bring the lens in just under the one-kilogram mark.
How much is the Sony 400mm f4.5 GM OSS supposed to cost?
The rumors currently going around name a price of about $3,000. Compared with other Sony telephoto lenses, that figure is the questionable part.
Is the Sony 400mm f4.5 lighter than the Nikon Z 400mm f4.5 VR S?
If the rumored 994 grams are correct, the Sony would be 166 grams lighter than the Nikon Z 400mm f4.5 VR S at 1,160 grams.
Will the new Sony 400mm be a G or a GM lens?
The current rumors name it GM OSS. Since the details largely rest on the same original source, the final product name remains to be seen.
Can the Sony 400mm f4.5 be used with teleconverters?
The lens itself is not officially confirmed, and teleconverter support is not part of the rumor either. If the lens works with Sony’s teleconverters, the 1.4x TC would give you 560mm at f6.3 and the 2x TC 800mm at f9 on paper.
How heavy would the combination with a Sony α7R VI be?
Based on the rumor, the lens weighs 994 grams, and the Sony α7R VI body weighs 713 grams. Without a teleconverter, the combination would come to 1,707 grams. With the 1.4x TC it would be 1,874 grams, and with the 2x TC 1,914 grams.
Why would a 400mm f4.5 under one kilogram be interesting for wildlife photography?
The low weight could be a clear advantage on longer hikes, when traveling, when shooting handheld, and on long days in the field. At the same time, you would have to accept less light than with a 400mm f2.8.
All open rumors about Sony cameras and lenses are collected under Sony Rumors.
Sources
- FredMiranda forum: “New Lenses?”, original post from September 3, 2026
- SonyAlphaRumors, September 4, 2026: leak with weight, dimensions, and price
- SonyAlphaRumors, September 6, 2026: reported announcement date
- Photo Rumors, September 4, 2026
- Sony Addict, September 4, 2026
- Camera Jabber, August 9, 2026: report on alleged engineering prototypes
- SonyAlphaRumors, March 20, 2026: early report on shorter 400mm and 600mm prototypes
- Nikon USA: official data and list price of the NIKKOR Z 400mm f/4.5 VR S ($3,249.95)
- Sony: official data for the FE 100-400mm F4.5 GM OSS
- Sony: official data for the FE 300mm F2.8 GM OSS
- Sony: official data for the FE 400mm F2.8 GM OSS
- Sony: technical specifications of the α7R VI (713 g with battery and memory card)
