Fujifilm has filled the gap between its 200mm f/2 and 500mm f/5.6 X-mount primes. The new FUJINON XF400mmF4.5 R LM OIS WR is a 400mm super-telephoto (609mm equivalent on APS-C) aimed at birds, motorsports, and aircraft — the same sports-and-wildlife brief DPReview and B&H Explora use for the launch. Fujifilm says the 200 / 400 / 500mm set now covers about 305mm to 762mm in full-frame terms.
U.S. list price is $3,199.95 ($3,899.99 in Canada). Fujifilm says the lens will be available mid-September 2026. You can pre-order now at B&H Photo Video.
A 609mm-equivalent prime you can actually carry
The optical formula is 21 elements in 14 groups, with two Super ED and four ED elements. Maximum aperture is f/4.5, minimum f/22, on a 9-blade diaphragm. Official measurements: about 104.5 × 239.5mm, 1,245g without cap and hood (about 2.74 lb), 95mm filters, 4.1° angle of view. Closest focus is 2.75m from the focal plane, for 0.16× magnification.
Fujifilm put the center of gravity closer to the camera so the barrel is less front-heavy, and it rates optical stabilization at up to 5.5 stops (CIPA, pitch/yaw). That is the handheld pitch: 609mm-equivalent reach without automatically dragging a gimbal head into the field.
Teleconverters, AF extras, weather sealing
The XF1.4X TC WR takes it to 560mm (853mm equivalent). The XF2X TC WR goes to 800mm (1,219mm equivalent). Autofocus is an internal linear-motor group. There is a focus preset (SET), a focus-control button near the front of the barrel (AF-L / PRESET / AF), and a limiter that restricts hunting beyond 5m / 15ft.
The barrel is sealed at 20 points, specified down to 14°F / −10°C, with a fluorine-coated front element. In the box: FLCP-95 front cap, rear cap, hood, pouch, tripod collar foot, and a shoulder strap.
Fujifilm calls this some of the highest optical performance in the XF lineup; that is the company’s claim, not a lab result. What is on the spec sheet is a brighter, slightly shorter alternative to the XF500mmF5.6 for photographers who wanted a native prime between the 200mm f/2 and the 500mm.