Sony’s 400mm and 600mm lenses weigh almost the same — but light and framing decide the winner

Sony’s FE 400mm F4.5 GM OSS and FE 600mm F6.3 GM OSS offer near-identical weight and handling, but their different reach and apertures make them suited to distinct wildlife, bird and sports photography needs.

Sony’s FE 400mm F4.5 GM OSS and FE 600mm F6.3 GM OSS sit closer together in practice than their specifications might suggest. According to Sony’s launch material and subsequent hands-on coverage from DPReview, both lenses are built around the same basic idea: super-telephoto reach in a package that stays just under 1kg, with the 400mm weighing 994g and the 600mm 995g. That near-identical mass changes the buying decision. The real question is not which lens is lighter, but which focal length better matches the way you shoot birds, wildlife or sport.

The extra reach of the 600mm matters most when distance is fixed. On the same camera, from the same position, 600mm renders a subject 1.5 times larger than 400mm in linear terms. That makes the longer lens the more obvious choice when the subject is small in frame, access is restricted or a barrier keeps the photographer from moving closer. The trade-off is compositional freedom: the tighter angle of view leaves less surrounding space, which can make it harder to keep fast-moving subjects fully framed. TechRadar’s review notes that both lenses are aimed squarely at wildlife and sports work, where that difference in framing can be decisive.

Aperture is the other major dividing line. The 400mm opens to F4.5, while the 600mm reaches F6.3. That one-stop gap means the shorter lens admits roughly twice as much light at the same shutter speed and scene brightness. In practical terms, that can allow a faster shutter speed or a lower ISO setting, both of which matter when subject movement is part of the challenge. Stabilisation helps with camera shake, but it cannot freeze a running athlete or a bird in motion. Sony’s launch claims, echoed by review coverage, place both lenses in a handheld-friendly category, but the brighter aperture of the 400mm gives it an advantage when the light is limited.

Handling is another area where the two lenses are strikingly close. DPReview’s hands-on report says the designs and controls are broadly similar, with only a 21mm length difference between them. Sony lists the 400mm at 242mm long and the 600mm at 263mm, with both having a maximum diameter of about 108mm. In other words, the 600mm asks for slightly more bag space, but not a meaningfully different carrying experience. That is important for photographers who want long reach without the bulk usually associated with super-telephoto primes.

Both lenses also support Sony’s optional 1.4x and 2x teleconverters, which extend their usefulness but do not turn them into zooms. On the 400mm, those accessories yield 560mm F6.3 or 800mm F9; on the 600mm, they produce 840mm and 1200mm equivalents. The cost is reduced maximum aperture, so the photographer must weigh extra reach against the loss of light and the operational inconvenience of changing accessories in the field. Sony’s statement and later reviews describe the lenses as sharing dual XD linear motors, optical stabilisation and configurable controls, all of which reinforce their professional positioning.

Price remains a final practical filter. TechRadar reports US pricing of $2,699 for the 400mm and $3,699 for the 600mm, matching Sony’s launch positioning of the pair as premium optics. Sony said the lenses would ship from October 2026, and the company’s US store listings later reflected availability differences between the two models. For buyers choosing between them, the decision comes down less to headline specifications than to how much reach they need, how often they work in poor light and how consistently they can control subject distance and framing.