Sony has unveiled two new G Master super-telephoto prime lenses that put an unusually strong emphasis on portability. The new FE 400mm F4.5 GM OSS and FE 600mm F6.3 GM OSS are aimed at photographers shooting birds, wildlife and sports, and Sony says they are the world’s lightest interchangeable lenses in their respective classes.

The numbers are striking. The FE 400mm F4.5 GM OSS weighs approximately 994 grams without its tripod mount, while the FE 600mm F6.3 GM OSS comes in at approximately 995 grams. Sony’s claim covers 400mm lenses with an aperture of F4.5 or faster and 600mm lenses with an aperture of F6.3 or faster for full-frame digital cameras, based on its September 2026 survey.

That sub-1kg weight is more than a headline specification. Sony has designed the two lenses around handheld shooting, with their center of gravity positioned closer to the camera body rather than toward the front of the barrel. The idea is to make it easier to keep a distant subject framed, follow moving animals or athletes, and pan while shooting without immediately reaching for a tripod or monopod.

The FE 400mm F4.5 GM OSS measures approximately 108mm in diameter and 242mm long, while the FE 600mm F6.3 GM OSS has the same maximum diameter and stretches to 263mm. Both are therefore considerably more manageable than the enormous fast-aperture super-telephoto primes that traditionally occupy this part of Sony’s lineup.

The 400mm is the more versatile of the two for photographers who want a balance between reach and environmental context. Its 400mm focal length can fill the frame with wildlife while still leaving enough of the surrounding environment visible. The 600mm, meanwhile, is built for situations where getting physically closer simply isn’t practical, giving photographers more reach while allowing them to maintain distance from their subjects.

Both lenses use Sony’s G Master optical design, including three Super ED elements and one ED element to control chromatic aberration and other optical imperfections associated with extreme focal lengths. Sony has also included its Nano AR Coating II to reduce ghosting and flare, particularly when shooting in challenging backlit conditions.

An 11-blade circular aperture is used to produce the smooth out-of-focus rendering associated with Sony’s G Master range. Sony says the optical design and manufacturing process also optimize spherical aberration to help maintain the characteristic G Master bokeh.

Autofocus is another important part of the design. Each lens uses two XD Linear Motors paired with a control algorithm developed specifically for the lenses. Sony says the system provides fast, precise and quiet focusing for subjects that don’t exactly have a habit of sitting still.

The lenses are also compatible with the Alpha 9 III’s continuous shooting system at up to 120 frames per second with AF/AE tracking, according to Sony’s testing. That makes the new primes particularly interesting for sports and wildlife photographers who need both long reach and fast subject tracking.

Optical image stabilization is built into both lenses, helping counter camera shake when shooting handheld at 400mm and 600mm. They also support compatible camera bodies’ Active Mode stabilization and coordinated stabilization controls. For video shooters, Sony says the lenses support compatible bodies’ breathing compensation feature as well.

Sony hasn’t forgotten about physical controls, either. Both lenses feature four customizable focus-hold buttons around the barrel, along with a function ring, focus-range limiter, Full-time DMF switch, focus-mode switch and image-stabilization mode switch. That gives photographers plenty of ways to configure the lens for a particular shooting style.

And when 400mm or 600mm isn’t enough, Sony’s optional teleconverters can take things considerably further. The FE 400mm F4.5 GM OSS can reach 560mm with the 1.4x converter and up to 800mm with the 2x converter, while the FE 600mm F6.3 GM OSS can reach 840mm or 1,200mm respectively.

Both lenses are designed for outdoor use with dust- and moisture-resistant construction and a fluorine coating on the front element to help repel contaminants. Sony notes that the lenses are designed with dust and moisture resistance in mind but are not completely sealed against dust or water droplets.

The new lenses also occupy an interesting middle ground in Sony’s super-telephoto lineup. Rather than trying to replace the company’s huge, fast and expensive flagship primes, the 400mm F4.5 and 600mm F6.3 focus on making serious super-telephoto shooting considerably easier to carry and more approachable.

Sony says both lenses will go on sale toward the end of September 2026. The FE 400mm F4.5 GM OSS is priced at approximately $2,699.99 in the U.S., while the FE 600mm F6.3 GM OSS costs approximately $3,699.99. In Europe, Sony lists approximate prices of €2,800 and €3,900, respectively, while UK pricing is around £2,400 and £3,300. Pricing varies by region.

For photographers who spend hours walking around with a super-telephoto lens waiting for a bird, athlete or wild animal to appear, the biggest feature here may simply be the one that doesn’t sound particularly glamorous: weight. Getting a 400mm or even a 600mm prime down to roughly 1 kilogram changes the practical experience of using that much reach, and Sony is betting that photographers will take advantage of it by leaving the tripod at home more often.