Review by Klaus Schroiff, published October 2022

Introduction

The build quality is superb, although you can expect no less at this price point. The lens does not extend during zooming. It is also weather-sealed and freeze-proof down to -10C. The zoom and focus control rings operate smoothly. Fujifilm implemented focus-stop buttons at the front of the lens. At the rear, you'll find various switches for focus modes & range and the aperture ring. Designing a lens with such a slow max aperture resulted in some debates within the Fujifilm community. However, an obvious advantage of this decision is the surprising compactness and low weight of the lens. A "900mm" lens weighing just 1.6Kg is quite an achievement. In absolute terms, this is still quite heavy, of course, and Fujifilm added a dedicated tripod mount (Arca-Swiss compatible). A deep, barrel-shaped lens hood (with a window for using polarizers) is also provided. It's a bit unfortunate that the hood is black-colored and prone to scratches - probably an opportunity for third-party companies to fix this.

The AF is very fast and silent. Manual focusing is very precise. The optical image stabilizer is rated with a gain of up to 5 f-stops. Given the slow speed of the lens, this is also needed. That being said - this isn't a silver bullet regarding the typical target applications where fast shutter speeds are often required to freeze the action. We haven't found any info on whether the gain increases when combined with in-camera IS (our test camera doesn't feature IBIS).

There has been some confusion regarding the compatibility with older Fujifilm cameras (including our little X-T30). The primary functions of the lens are, of course, working just fine, but the following features are only supported on newer cameras - the “Focus Selector” (AF-L, PRESET, AF), the “Focus Preset Button,” and the “Focus Control Buttons.” While zooming, the focus is also not automatically adjusted until the zooming stops on older cameras. The X-S10, X-T4 and X-T3 require a firmware update to support all aspects of the XF 150-600mm f/5.6-8 R LM OIS WR.