Autofocus performance

ISO 16,000 | 1/1000 sec | F2.8 | Canon 70-200mm F2.8L IS @ 80mm

We've already covered all that's new and revamped about the EOS-1D X Mark III's autofocus system, but how does it actually perform? In short, whether you're using the optical viewfinder or the rear screen, this is the best-focusing Canon camera yet.

Key takeaways:

  • New high resolution pixel-grid AF module and 400,000-pixel RGB+IR sensor (read more here)
  • 'People Priority' mode works pretty well, even in fast-paced situations
  • New 'Case Auto' mode works reasonably well, but choosing one of the AF cases yourself gave better results in our experience
  • Against competing mirrorless systems, the spread of AF points in the viewfinder is constricting
  • You'll get the absolute best autofocus performance in live view, but camera's form factor and weight might make this impractical

Case Auto and People Priority

We paid particular attention to the 1D X III's 'Case Auto' and 'People Priority' settings while using Canon's Intelligent Tracking and Recognition system (iTR). We also experimented with 'Case 1,' which is the 'versatile multi-purpose setting' that Canon has claimed to have improved. You can find out more about Canon's updated AF cases here.

AF cases have been simplified, with Canon claiming an improvement in Case 1 for a wide variety of uses, as well as the addition of Case Auto which will automatically adjust parameters on the fly.

On previous Canon cameras, we found the autofocus system to be highly effective: so long as you used a zone of points and made sure to choose an appropriate autofocus 'case' for your subject. This contrasted with, say, Nikon's D5, where we could pretty much set it on 3D Tracking and forget it (and this is to say nothing of Sony's a9-series cameras and their impressive tracking capabilities).

Autofocus subject tracking through the viewfinder

So let's take a look at how well this revamped system works. This exercise examines how well the camera can both maintain focus on an approaching subject while also having to recognize the subject and track it around the frame. We tried both Case Auto and Case 1, and found Case 1 to give a slightly better hit rate (around 80% instead of 75%). Demonstrated here is Case 1 at a burst rate of 16fps.

For all runs, the AF points stuck pretty tenaciously on our riders head as he weaved through the scene, but we do see some shots that are mis-focused in the middle of the run; this is behavior we've long noticed with Canon's iTR tracking. So, it's a solid performance, if not up to the high standards of its peers.

Autofocus subject tracking using live view

Alright, now let's flip the mirror out of the way and use the EOS-1D X III in live view. As with all of Canon's latest cameras, the 1D X III comes with Dual Pixel autofocus, and we've found it to be generally effective for a variety of subjects. This latest implementation also now has the same autofocus cases and People Priority modes as the viewfinder system. Here, we used Case 1 at a burst rate of 20fps with the mechanical shutter.

While there are still a couple of soft images, the overall hit rate for live view was noticeably higher than using the viewfinder. Impressively, the camera also recognized the cyclist's head and consistently followed that around the frame despite the mask and sunglasses.

So if you want the best AF subject tracking performance the 1D X III is capable of, it's best to switch into live view. But of course, we had the benefit of a tripod here: hand-holding this camera out in front of your face with a 70-200mm F2.8 lens mounted isn't much fun.

Now let's take a look at how the camera performed in some real-world scenarios.

People Priority through the viewfinder

For this college basketball game, we exclusively shot the 1D X III in Case Auto and with People Priority enabled to see how these new features work with fast, unpredictable action in less-than-ideal lighting.

In the above images, we initiated autofocus tracking on the jersey of the player on the right, and you'll see how within a few frames, the camera jumped to recognizing and tracking his head. Not too bad for an optical viewfinder autofocus system, but click through to larger images and you may notice that some shots are a bit 'soft,' as focus isn't truly accurate on the intended subject.

Alright, so then what happens if a person's face is obscured?

Despite the main subject's face being obscured momentarily, the camera jumps to another portion of the subject that is at approximately the same distance, and then jumps back to the player's head again when it's visible. So that's promising.

Unfortunately, further scrutiny shows that the camera's iTR tracking still isn't quite up to the 'set it and forget it' standards of its competitors, as we saw with the weaving bicycle earlier.

The above burst covers several aspects of the system we observed frequently when using Case Auto and People Priority. As you go through the sequence, you'll see the camera switch from head-detection to body detection and back again, as the player's head leaves and re-enters the spread of the autofocus points (frames 2 - 4). In spite of continuing to track the body of the player during these frames, image 3 is noticeably softer than 4.

As the intended subject nears the edge of the AF area in frame 7, the camera switches to focusing on the opposing player, and continues to do so until the Seattle player re-enters the AF area in image 11. That the camera loses the Seattle player in frame 12 and then regains him in frame 13 is somewhat expected, as autofocusing while zooming is a bit of a torture test for even the best cameras.

There were times we also saw some unnecessary hunting, even with less-erratically moving subjects.

This is just an example of two shots out of a sequence that alternated almost every shot between in-focus and just-out-of-focus; the camera would capably track the subject's face with the AF points, but proved to be a bit too 'jittery' in focusing on the portion of the subject actually under those AF points. Depending on your AF Case settings, this 'nervous' hunting behavior is something we've noticed on nearly all Canon DSLRs for years.

Dual Pixel AF in live view

We frequently praise Canon's Dual Pixel AF technology, and for good reason: it's an effective system with an implementation that makes it easy to use. In fact, we generally find that it lags only Sony's latest autofocus implementations. That said, the performance is noticeably improved on the EOS-1D X Mark III.

We'd recommend setting the camera up to let you choose which subject to track, rather than letting the camera do it for you. This is accomplished by changing the 'Initial Servo AF pt' setting on the fourth page of the AF section of the menus; instead of auto, select the third option, 'AF Pt set for [focus areas]'. Now, if you place the AF area over an object, it will track that object, and if you place the AF area over a face, it automatically switches to face and eye detection.

Screencapture from Canon Digital Photo Professional.
ISO 1250 | 1/200 sec | F2 | Canon EF 35mm F2 IS USM

In the above image, we switched into live view to capture this overhead angle, with the two students in the foreground and the sparks flying in the background. Note how Dual Pixel locked onto the individual's face and stayed locked onto it, even though he's facing down at a pretty extreme angle. And if the individual looks away, the camera is smart enough to continue tracking that person's head instead of jumping off to someone else. Basically, face detect in live view is downright impressive on the 1D X III.

Screenshot from Canon Digital Photo Professional.
ISO 51200 | 1/800 sec | F5.6 | Canon 100-400mm F4-5.6L at 400mm

For the above image, we left the (subpar) framing as it is, to illustrate a) how difficult it is to frame moving subjects at 400mm in live view, even with a monopod, and b) just how effective the 1D X III is at finding faces in abysmal lighting and at a small size in the frame. It doesn't find eyes at this distance, but it confidently held onto that player's face.

So what's the verdict?

For those professionals that largely prefer to use a single point or zone and follow the action themselves, the EOS-1D X III will reward them with an extremely high hit rate whether using the optical viewfinder or live view – but we find this to be true across a wide variety of cameras on the market today. We heavily weight our assessments here on subject tracking because it remains a key differentiator among various cameras.

In terms of subject tracking, the EOS-1D X Mark III is the best-autofocusing Canon camera that we've yet tested

And so in terms of subject tracking, the EOS-1D X Mark III is the best-autofocusing Canon camera that we've yet tested. While its viewfinder autofocus system still isn't quite as reliable at subject tracking as the best of its peers, it's a marked improvement over the previous 1D X Mark II. And live view autofocus is really impressive: Canon has very nearly closed the gap here with Sony's autofocus performance and implementation in its a9-series cameras. We're pretty excited for this live view performance to (hopefully) trickle down to more compact models in the future.