Autofocus speed and accuracy

The X-T1's autofocus is, at its best, extremely quick and unerringly accurate. It performs best with internal focus lenses such as the XF 18-55mm F2.8-4 R LM OIS and XF 55-200mm F3.5-4.8 R LM OIS, which are also near-silent in operation. However it's hugely lens-dependent - probably more so than any of the X-T1's peers - and with the older X-system primes it can still feel decidedly sluggish. This is most obvious with the XF 60mm F2.4 R Macro, which has to rack the lens barrel backwards and forwards to focus. But more surprisingly, we also saw a fair bit of hesitancy and hunting with the new, and otherwise wonderful, XF 56mm F1.2R portrait lens.

Autofocus accuracy

One huge advantage of mirrorless cameras like the X-T1 over SLRs is autofocus accuracy with fast primes. Almost all SLRs struggle to focus fast primes sufficiently accurately to make the most of high resolution sensors, because the autofocus system is entirely separate from the image sensor itself. But mirrorless cameras determine focus by looking at the actual image projected by the lens onto the sensor, which is an inherently more accurate way of doing things. Enthusiast SLRs offer focus microadjustment settings as a workaround, but even this isn't always sufficient to overcome their limitations.

X-T1 + 56mm F1.2, 1/4000s F1.2 ISO 200 100% crop

Once the X-T1 has decided on a focus distance, you can generally be sure that it will have nailed it precisely. For example it can focus the 56mm F1.2 lens sufficiently accurately to get consistently sharp images wide open every single shot, regardless of subject distance or the position of the AF area within the frame. This contrasts very favorably with our recent experiences trying to persuade the Nikon D7100 to work with the AF-S Nikkor 58mm f/1.4G properly; even with AF microadjustment set, the camera simply couldn't focus the lens accurately at all subject distances.

What this means is that the X-T1 is entirely capable of making full use of the optical quality of Fujifilm's excellent set of fast primes (including the 23mm F1.4, the 35mm F1.4, and 56mm F1.2) with relative ease. There's no need to mess around with calibrating against focus test targets to get the camera set up - it all just works, out of the box. If you want one really good reason why you might abandon the optical viewfinder of an SLR, with all of its manifest advantages, for an electronic version, this could be it.

Continuous Autofocus

The X-T1, despite having the same sensor and processor as the X-E2, adds a major new trick, namely continuous autofocus during high-speed shooting. Set the focus mode to AF-C and the drive mode to CH, and the camera highlights the 9 central AF points which correspond to the sensor's phase detection area. As long as you hold the subject in this region, the camera will attempt to hold focus on it.

Below is an example of how well this can work, shot in CH mode using the XF 55-200mm F3.5-4.8 R LM OIS lens at 55mm. This shows the final 10 frames of a 23 shot burst, representing a little over 3 seconds of shooting time. The X-T1 has successfully held focus on the cyclist riding towards the camera, which few other mirrorless cameras can do (and older Fujifilm cameras wouldn't even try).

Frame 1
Frame 2
Frame 3
Frame 4
Frame 5
Frame 6
Frame 7
Frame 8
Frame 9
Frame 10

There is one caveat though; the camera started out shooting at 8fps in this sequence, but by the time it reached the point we're showing here, it had slowed right down due to the time taken to change the focus position between shots. At the end of the sequence it was shooting at closer to 4fps (which is similar to the practical AF tracking speed we saw from the Olympus OM-D E-M1).

This may sound like a criticism, but it isn't really. The X-T1 can still track focus on a subject moving quite quickly towards the camera, and what's more, all of the frames are sufficiently in-focus to be usable. This at a stroke goes a long way to addressing one of the few remaining areas where SLRs could claim clear superiority over mirrorless cameras.

Face detection

The X-T1 has a face detection AF mode, and unlike on the X-E2, it can be quickly enabled or disabled from the 'Q' menu. It's probably not something you'd want to use all the time, however, as when it's turned on the camera will no longer let you manually select an off-centre focus point, even when it can't detect a face in the scene. It also overrides your metering preference, locking the camera into multi-pattern mode, and inactivates the autofocus lock button into the bargain. In general other manufacturers' systems only take over focus and exposure when they actually spot a human subject (which is precisely what you want them to do).

One particularly strange quirk is that when face detection is turned on and the focus mode is set to Single AF, then if you start to record a movie, the camera switches to Continuous AF, for no obvious reason. However this is arguably the least of the X-T1's problems in movie mode.

Fujifilm's face detection is reliable enough when your subject is looking at the camera, but is much less consistent when they're side-on. Overall we think it can be worth using when you're specifically shooting portraits (or at least, trying out to see if it meets your needs). But the rest of the time we'd turn it off.