Hands on: Fujifilm XF 400mm F4.5 R LM OIS WR review

Fujifilm has unveiled a new X-mount super-telephoto prime lens, the Fujinon XF400mmF4.5 R LM OIS WR. This is the second such lens in Fujifilm's current X-mount range, with the original XF500mmF5.6 R LM OIS WR remaining the sole competitor. The 400mm optic is 90 grams lighter and 16mm shorter than its counterpart, while retaining a maximum aperture of f/4.5, making it slightly faster.

Equivalent to 609mm on full-frame cameras, this lens is tailor-made for sports and wildlife photography. It can also be paired with Fujifilm's 1.4x and 2x teleconverters to achieve full-frame-equivalent focal lengths of 853mm and 1,219mm respectively.

The XF400mmF4.5 boasts a distinctive silvery-white barrel finish to reflect solar heat, akin to the XF500mm f/5.6. Alongside the typical aperture ring, it includes three switches: a focus limit switch to prevent focus hunting at close ranges, an OIS on/off selector, and a focus preset function to instantly shift focus to a pre-defined position.

The lens features an internal focusing mechanism with a wide manual focus ring for accurate manual focusing. Autofocus is powered by a high-speed linear motor, while offering up to 5.5 stops of optical image stabilization for handheld photography.

Weighing in at 1,245g, the XF400mm is surprisingly lightweight for a fast super-telephoto lens and feels well-balanced when mounted on the X-H2s body. Even with the lens hood attached, the setup remains unobtrusive, allowing for extended handheld shooting without issue. The lens's weather-sealing, with 20 sealing points, and a fluorine coating on the front element guard against water and dust ingress.

In the rain, the XF400mm performed flawlessly, and the deep lens hood effectively kept droplets off the front element. The lens features a 21-element optical stack arranged in 14 groups, aiming to minimize chromatic aberrations by biasing weight towards the rear of the lens.