Autofocus

Autofocus hasn't been a traditional strength of the X Series, the AF system has been comparatively simplistic and many of the early lenses were designed in a way that prioritized image quality over focusing speed. The X-T2 is a huge leap forward in many respects.

The phase detection area on the X-T2 is quite small by contemporary standards but extends beyond the thirds of the image in each dimension, so gives a similar degree of freedom of composition as a similarly priced DSLR.

As with the X-Pro2, the X-T2 features distance-aware phase detection elements across a larger part of its sensor than previous models and the X-T2 also gains the ability to fine-tune the autofocus behavior to help it understand, and keep focus on, your chosen subject.

We tested and shot the X-T2 in a variety of circumstances and found it by far the most capable camera from Fujifilm yet. As before, you can either select a single AF point for the camera to focus on, choose a 3x3, 5x5 or 7x7 'zone' or set the initial AF point and let the camera try to track it around the frame.

Face/Eye Detection

Oddly, the camera can only conduct Face Detection while using contrast detection AF, rather than using image analysis to choose which focus point to use and then using phase detection to acquire focus. This means you get a high level of precision but with reduced speed (especially in low light) and, particularly with slow to focus lenses, significant hunting. However, in good light with a posed subject, eye detection is a useful addition when working with fast primes.

AF-C fine tuning

The X-T2 gains the ability to fine-tune the behavior of autofocus system, with five use-cases that give the camera some information about the behavior of your subject, so that the AF can respond accordingly. Beyond this there's a sixth setting that lets you define your own setup by adjusting the three parameters that underlie the presets.

The three options help tell the camera which subject it should be focusing on and how that subject is likely to behave, to improve the continuous AF performance.

  • Tracking sensitivity defines how long the camera waits before refocusing if there's a sudden change in distance to the subject, which lets you tune the behavior for suddenly appearing subjects or preventing the camera getting distracted by obstacles in front of your subject.
  • Speed Tracking Sensitivity tells the camera how predictable the movement of the subject is likely to be (a constant rate or accelerating/decelerating).
  • Finally, Zone Area Switching defines whether the camera gives priority to the object at the center of the chosen focus zone or the nearest object within the zone, with an Auto option that prioritizes the first thing focused on.

Broadly speaking, you need to consider how responsive you want the camera to be and how predictable the movement of your subject is, when choosing a preset.

Performance

Despite the word 'tracking' occurring so much in these presets, Fujifilm advised us the camera's AF settings are primarily designed for working in Zone AF mode. And, sure enough, we had most success when using the X-T2 like an older DSLR - setting the approximate focus zone and trying to point the camera to keep that focus area over the subject, rather than expecting the camera to accurately track the subject around the frame.

In Zone Focus mode using a 3x3 zone, here with Tracking Sensitivity set 0 (zero tolerance for obstacles), Speed Sensitivity set to 1 (very predictable movement) and Zone Area Switching set to Auto, the camera is able to do a great job of anticipating the rider's movement and refocusing accordingly.

Subject tracking, where the camera attempts to follow a subject around the frame as well as in depth, is substantially improved too, though. Once the first focus lock has been achieved, the camera is very good at following the subject around the scene, so long as it remains within the phase detection region of the camera's sensor. At all but the lowest 'Tracking Sensitivity' setting, where the camera can be a little too keen to refocus on the background or other subjects, it's really very successful.

Our impressions are that the system is very heavily weighted towards the input from its phase detection system, as the performance is significantly better when there's a clear depth distinction between the subject and its surrounding. In other words, don't expect it to accurately target an eye on a face, or one person in a complex scene with other subjects. An isolated biker against a far background, though, is territory the X-T2 can easily handle, a definite improvement over predecessors.

Based on the roughly 1800 images we shot for this test, we'd conclude that AF Tracking is much improved, too. With the exception of a couple of mis-focused shots at one of the turns (including the first image in this rollover), the camera got over 90% of this 48 image sequence in good focus. However, this test does have a fairly unambiguous target well separated from its surroundings.

In this instance the AF-C settings were: 4 to reduce the habit of refocusing to the background, 2 because the subject's movement is not predictable and 'Front' to avoid the camera refocusing on the background when the subject is away from the center of the frame.

With fast-to-focus lenses, this is a tracking performance that puts it broadly on par with the likes of the Sony a6300 and Canon's 80D (with the upper-hand changing, situation to situation). This is a huge leap forward for Fujifilm but it's still short of the uncannily fast and persistent tracking performance of cutting-edge cameras such as the Nikon D500.

Close-up performance

Again, the camera takes a moment to initially find its subject, after which it does a good job of keeping track of what it's supposed to be focusing on. In this moderate indoor lighting the refocus speed has dropped so you can see the camera is in focus for less of the time. [Shot using Fujinon 16-55mm F2.8 LM]

Limitations

However, there are two substantial caveats to this positivity. Fujifilm expressly prioritized image quality over AF performance with its early lenses (particularly the wide-aperture primes) and these simply can't move their focus elements fast enough to take advantage of the X-T2's capabilities. As such, you'll only experience the camera's full performance with a select sub-set of the system's lenses. As well as failing to refocus quickly enough to keep up with subject movement towards or away from the camera, slower focusing lenses also delay the initial 'lock,' making subject tracking mode almost unusable.

The camera's focus slows considerably in low light - the contrast detection wobble taking much longer - no matter what lens you use.

The other concern for us was that the camera's performance drops significantly as the light level decreases. The camera appears be a true hybrid system, meaning it conducts a full contrast detection fine-tune hunt as part of every focus acquisition. This step in particular noticeably slows in lower light, making it difficult for the camera to achieve focus if the subject moves significantly during focus acquisition. However, it does mean that, if your subject is still enough, the accuracy remains high. In addition, the camera seems only to initiate tracking only once it's achieved the first focus lock, so this too becomes less reliable in low light.