FUJINON XF400mm F4.5 R LM OIS WR Announced – 609mm Equivalent Reach, 1,245g, 5.5 Stops of Stabilization

Lens News

by Alexandra ThompsonSeptember 7^th, 2026

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FUJIFILM has introduced the FUJINON XF400mm F4.5 R LM OIS WR, a new super-telephoto prime for the X Mount system. The 400mm lens provides a 609mm full-frame-equivalent field of view while weighing 1.245kg / 2.74 lb, with FUJIFILM placing particular emphasis on handheld mobility and balance for wildlife, sports, aviation, and other long-lens applications.

The lens features up to 5.5 stops of optical image stabilization, internal focusing driven by a linear motor, focus preset and limiter functions, weather-resistant construction, and compatibility with FUJIFILM’s 1.4x and 2x teleconverters. It is expected to ship in mid-September 2026 for $3,199.95 in the US and $3,899.99 in Canada. 

Long reach without the usual bulk

The XF400mm measures 104 x 239.5mm / 4.1 x 9.4in and weighs 1.245kg / 2.74 lb, giving FUJIFILM X-series users a 609mm-equivalent angle of view in a relatively compact package. FUJIFILM says the optical design also places the center of gravity closer to the camera body to reduce the front-heavy feel common with super-telephoto lenses and improve handling during extended handheld shooting. 

That balance is arguably more relevant than weight alone for photographers who spend long periods following birds, athletes, vehicles, or aircraft. Up to 5.5 stops of optical image stabilization further supports handheld use, particularly at a focal length where even small camera movements become obvious in the viewfinder. FUJIFILM rates the stabilization according to CIPA standards for pitch and yaw correction. 

The addition of the XF400mm expands the company’s X Mount super-telephoto prime range to cover 35mm-equivalent focal lengths from 305mm to approximately 762mm. The new lens sits below the XF500mm F5.6, which we covered when it was announced, while offering a faster F4.5 maximum aperture. X Mount users who prioritize zoom flexibility can also look to the XF150-600mm F5.6-8 as a related long-lens option.

Optical design and autofocus

The XF400mm uses 21 elements in 14 groups, including four ED and two Super ED elements intended to reduce chromatic aberration and maintain resolution at long focal lengths. The lens has a maximum aperture of F4.5, a minimum aperture of F22, and a nine-blade rounded diaphragm. 

Autofocus is handled by an internal focusing system driven by a high-speed linear motor. FUJIFILM describes the system as fast and near-silent, which is useful both for unpredictable subjects and for applications where AF noise needs to be kept to a minimum. 

Two additional controls are designed specifically to reduce reaction time. A focus preset function lets the user save a focus position and return to it using the SET button, while the focus limiter restricts autofocus operation to more distant subjects. The company specifies the limiter for subjects beyond approximately five meters. A Focus Control Button near the front of the barrel can be assigned through the Focus Select Switch to AF-L, PRESET, or AF. 

1.4x and 2x teleconverter support

The XF400mm is compatible with FUJIFILM’s XF1.4X TC WR and XF2X TC WR teleconverters.

With the 1.4x teleconverter attached, the focal length extends to 560mm, which FUJIFILM lists as an 853mm full-frame equivalent. The 2x converter extends the lens to 800mm, or 1,219mm equivalent. 

As with any teleconverter, that additional reach comes with light loss. A 1.4x converter reduces the maximum aperture by one stop, bringing the combination to approximately F6.3, while a 2x converter costs two stops, resulting in F9. For wildlife photographers working around dawn, dusk, or under tree cover, that trade-off between additional reach and available light will be an important consideration.

Built for field use

The lens barrel has 20 sealed points for dust and weather resistance and is specified for operation in temperatures down to -10°C. The front element also has a fluorine coating designed to repel water and resist smudges. 

The minimum focusing distance is 2.75m, with a maximum magnification of 0.16x. The lens uses a 95mm filter thread and includes a lens hood, tripod collar foot, pouch, and shoulder strap. 

Specifications

Who is the XF400mm for?

FUJIFILM is clearly positioning the XF400mm as a stills-first lens for wildlife, birds, outdoor sports, motorsports, and aviation. The combination of 609mm-equivalent reach, relatively low weight, image stabilization, focus preset, focus limiting, and weather resistance all point toward photographers working handheld and following fast or unpredictable subjects in the field. 

There are also features that could be useful for long-lens documentary and nature video, including internal focusing, optical stabilization, and a near-silent linear AF motor. However, FUJIFILM’s launch material does not make any specific video-oriented claims for the lens. For readers considering the lens as part of an X-series video setup, our  FUJIFILM X-H2S Lab Test provides a closer look at the moving-image performance of one of FUJIFILM’s higher-end X-series bodies.

For photographers already working with the X system, the more interesting question is therefore not simply whether 400mm is long enough, but whether 609mm-equivalent framing at 1.245kg / 2.74 lb and F4.5 offers the right balance of reach, speed, and portability for the way they work.

Price and availability

The FUJINON XF400mmF4.5 R LM OIS WR is scheduled to become available in mid-September 2026 at an MSRP of $3,199.95. The XF1.4X TC WR and XF2X TC WR teleconverters are sold separately. 

For wildlife and sports shooters, is the combination of a 609mm-equivalent field of view, F4.5 aperture, and 1.245kg / 2.74 lb weight more useful than simply having more reach? Let us know in the comments below.