Fujinon XF50-140mm F/2.8R LM OIS WR Review

This telephoto lens is of the highest grade among Fujinon lenses. It offers a constant F/2.8 maximum aperture throughout its zoom range and is completely weather-sealed, only the second weatherproof X-mount lens to date. As an XF lens, it features an aperture-ring, providing direct mechanical control over the aperture.

With a 50-140mm focal-range, the Fujifilm Fujinon XF50-140mm F/2.8R LM OIS WR
Fujifilm Fujinon XF50-140mm F/2.8R LM OIS WR is equivalent to a 75-210mm lens on a full-frame. Such focal-range is typical for a medium telephoto zooms used on 35mm film cameras for sport photography. Nearly every lens maker offers a similar 70-200mm constant-aperture lens for one or more mounts. The F/2.8 ones are favored for low-light while the F/4 ones are preferred for their lighter weight. For the Fuji X-mount, there is no similar third-party lens.

The XF50-140mm is the largest and heaviest X-mount lens. Its metal barrel has a smooth and luxurious finish. There are rings for focus, zoom and aperture, covering most of the lens. At the front, a fly-by-wire focus-ring turns very smoothly. This one is a metal ring with fine ribs for purchase. Behind it, the largest rings if the zoom ring. Its 2" width is covered in rubber ribs and provides excellent traction. A quarter turn is all it takes to zoom smoothly from 50 to 140mm.

The metal aperture-ring at the back of the lens is larger than it looks. Only the rear two-thirds are covered with metal ribs but the part labelled with F-stops turns as well. Since the aperture-range is constant, there are clear labels for each full-stop. Past F/22, there is an A position which enables the camera to select aperture. As usual, if a shutter-speed is selected on the camera, this puts it in Shutter-Priority mode. Otherwise, it would be in Program mode.

The aperture ring has detents for each 1/3 F-stop. The detents moderately firm which is a clear improvement over all other current Fuji X-mount lenses. Finally, with the XF50-140mm F/2.8R LM OIS WR, accidental changes in aperture are uncommon.

There is a rotating collar at the base of the lens barrel. A textured plastic knob enables the collar to freely rotate. There are markings but no detents for horizontal and vertical positions. A tripod mount attaches to the collar via two screws and a positioning pin guides the attachment in place. This is somewhat fiddly because all three must be aligned at once.

Right between the collar and aperture-ring, a small sliding button toggles built-in optical image stabilization. Fuji equipped the XF50-140mm F/2.8R LM OIS WR with state-of-the-art image-stabilization. It uses gyroscopes to compute drift and compensate for it during long exposures. Fuji claims over 4 stops of improvements over hand-holding. This is, as always, measured under ideal conditions yet it does manage often around 3 stops of improvements.

The XF50-140mm incorporates triple linear motors which help this lens achieve fast and nearly silent autofocus. These motors are placed at regular intervals around an inner focus-system that allows efficient AF in such heavy lenses. Also worth noting is that zooming is also internal. Together this means that the lens does not change its size or balance during zooming or focusing.

The level of construction of this lens is impressive. Not only is it weathersealed but freezeproof down to -10C as well. At almost 1kg in weight, this Fujinon is far from light-weight. Despite being designed for APS-C coverage, it is comparable in size to similar full-frame lenses and notably heavier than APS-C offerings. Fuji did everything possible to make this a premium offering, including providing a sturdy windowed lens hood, like Pentax does with their own DSLR lenses.

Since all Fuji mirrorless cameras use the same 1.5X crop APS-C sensor, the XF50-140mm always gives a 32° to 11.6° angle-of-view range. Given that the minimum focus-distance is also fixed at 1m regardless of zoom position, this lens offers its maximum magnification at 140mm. This turns out to be 0.12X, confirming that this particularly lens is not suitable for close-ups.

The 7-blade aperture closes down to F/22, up from the headline maximum of F/2.8. The blades of the iris are rounded to render bokeh as smooth circles. Depth-of-field can be quite shallow, particularly near its maximum magnification where focal-length and bright apertures work together to neatly isolate a subject.

Optically, the Fujinon XF50-140mm F/2.8R LM OIS WR delivers top-notch image-sharpness. Towards the wide-end of the zoom, most of the frame is extremely sharp from wide-open. It only takes stopping down 1/3 of a stop to achieve perfect sharpness nearly everywhere. The extreme corners are very slightly softer than the center. Stopping down just past F/4 makes these very sharp.

Sharpness remains excellent around the image-center at 90mm, which is near the middle of the zoom. At that point though, corners are not as sharp as before until stopped down to F/4.5 at least. Still, only the extreme corners show any softness. The rest of the frame is sharp from wide-open.

At 140mm, the entire frame exhibits some softness wide-open. This disappears almost completely at F/3.2 which only leaves, again, a very slight softness at the extreme corners. Those sharpen up completely by stopping down to F/4.

There are no signs of vignetting or chromatic aberrations. Light transmission is extremely uniform and this lens resists impressively well to flare, thanks to Fuji's unique High Transmittance Electron Beam Coating (HT-EBC), now applied in conjunction with Nano Gradient-Index coating which controls refraction as light enters glass.

With 23 glass elements, including 5 ED ones, the XF50-140mm is extremely well corrected. There is only the slightest sign of barrel distortion at wide-angle. This disappears immediately when zoom in, delivering natural-looking images with straight lines remaining straight.

As the flagship lens in the Fuji lineup, the XF50-140mm F/2.8R LM OIS WR
Fujifilm Fujinon XF50-140mm F/2.8R LM OIS WR set high expectations. Luckily, it fulfills them with ease, delivering a superb all-around performance. Sharpness is excellent throughout the zoom range, only softening a little wide-open near 90mm. The sophisticated optical image-stabilization system works very well, while the triple linear motors make the lens focus quickly and extremely quietly.

The construction of the XF50-140mm is top-notch. This lens is built like a tank with large focus and zoom rings which turn very smoothly. The metal aperture ring has improved detents which make this lens much less accident prone than other ones in the XF-series.

Owing to its high-end construction, the XF50-140mm is huge and heavy. At nearly 1kg and 18cm long, it wipes clean the benefit of a mirrorless system, exceeding the bulk of even similar lenses for APS-C DSLRs. Unsurprisingly, with its quality and ultimate performance, this is also the most expensive X-mount lens on the market.