The Fujifilm X-E3 uses the same autofocus system as its sibling, the X-T20, with a phase detection area that covers 70% of the frame vertically and 50% horizontally. There are 325 total selectable points. By comparison its coverage is nowhere near as thorough as the Sony a6300 - one of its main competitors - which offers 100% coverage with 425 selectable points.

An updated AF Tracking algorithm has been introduced in the X-E3 (it will make its way to other FujiFilm models via firmware) - its suppose to make it easier to track smaller and faster subjects. To find out if the updated algorithm results in real world improvements to hit rate and consistency, we put the X-E3 through our standard AF tests.

Continuous AF

But before testing subject tracking, we wanted to see how well the X-E3 can drive its lens to maintain focus on a subject approaching in a straight line using a single focus point. So we set the camera to Single Point AF (using the middle point size) and had our subject, Richard, bike directly toward the camera as we shot at 8 fps.

The results of this first test are quite good, the X-E3 maintains focus for the majority of the shots in the sequence. It seemed to fall behind slightly toward the middle of the burst, only to catch back up. These results are similar to what we observed with the X-T20 and other cameras in this class, meaning the X-E3 is quick to refocus on a moving subject as long as you keep your AF point over it and use a sufficiently fast-to-focus lens.

Subject tracking

In our next text we wanted to see how the X-E3 would handle a subject moving toward the camera, but in an irregular pattern. This is where 'Tracking' AF mode comes in: meaning the camera has to recognize and follow a subject whose movement it can't predict. For this test we instructed our subject to try to stay within the camera's horizontal phase detect area, which is fairly narrow, and weave toward the camera.

As you can see from the roll-over, the hit rate is not as good as our depth tracking test, with at least 6 images out of focus. And in another run, where our subject ventured too far off center into the contrast-detect AF regions of the frame, the hit-rate dropped further.

However it's not all bad news, the images that aren't in focus seem to have missed not because the tracking algorithm got confused but because the AF system simply could not keep up. Still, missed shots are missed shots and It seems that despite possible improvements made to the algorithm, the X-E3's 'Tracking' AF mode is not consistent enough for us to recommend it for serious sports or action photography.

Close range AF

Next we performed our normal close-range AF test to simulate photographing friends/family in dimly-lit social settings, using a wide angle lens. In the first part of the clip below, we set the camera to 'Tracking' AF and tried to maintain focus on our subjects as we move around, firing shots in the Single Shot drive mode.

Sample photoSample photoSample photoSample photoSample photo

We are pleased to report that improvements to the X-E3's tracking do seem noticeable in part 1 of this demo: not only do the AF points seems to keep up with the camera's movement (unlike on previous Fujifilm cameras) but the hit rate is also improved over previous Fujifilm cameras (closer to an 80% hit rate with the XE-3 compared to 70% the X-T20).

The second part of the clip demonstrates the camera's Face Detect mode (as opposed to using the Tracking AF), in Continuous AF mode. Again we left the camera in Single Shot drive mode. Though it might seem like the X-E3 is keeping up, the result are a much lower hit rate (around 50%) compared to using the 'Tracking'. In short, when it comes to human subject recognition, the X-E3's subject tracking mode is a far more reliable bet than the Face Detect mode. This isn't too surprising: in the past Face Detect forced the camera's AF system into CDAF-only mode, and while it appears improved on the X-E3, it's still unreliable - particularly with slower to focus lenses.

'When it comes to human subject recognition, the X-E3's Subject Tracking mode is a far more reliable bet than the Face Detect mode.'

For the final part of the clip we switched the cameras back to Tracking AF but in its 8 fps drive mode to see if the X-E3 can track at a close-range in challenging light while also firing at its top speed with AF-C. Though the results look good in the video clip, our gallery of images tells another story: the AF system struggles to keep up as the camera moves toward and away from our subjects. It gets worse with slower-to-focus lenses: a reminder that most Fujifilm cameras' AF performance are particularly lens-dependent relative to other manufacturers. [More that the lens speed is more variable than most of its rival systems]

Video Quality

The Fujifilm X-E3 shoots 4K video at up to 30p from the full width of its sensor. To achieve this means pixel binning, so its footage isn't as crisp and detailed as the X-T2's, but it does mean you get the full field-of-view of your lenses (the X-T2's video comes from a cropped region).

This means it can't match the level of detail from the Sony a6300 (which oversamples and downscales its 4K footage), but in real-world shooting it's not too far behind the Nikon D7500's output, which is shooting using a 3840 x 2160 region of its sensor. While the Nikon's footage is more detailed, the use of 1:1 pixel shooting entails a significant (1.5x) additional crop, making it harder to achieve a wide-angle field of view than the Fujifilm.

In real-world use the Fujifilm exhibits significant rolling shutter, though.