The Canon EOS M5 uses the same Dual Pixel autofocus system as the company's EOS 80D, so it should offer broadly similar performance, although with the caveat that there will be some dependence on lenses (Canon's EF-M 22mm F2 pancake lens is particularly slow to focus). In any case, let's see how the EOS M5 fares in its own tests.

Dual Pixel AF

This implementation of Canon's 'Dual Pixel AF' design first appeared in the EOS 70D. It features left and right-looking pairs of photodiodes at each pixel position. This means the camera can view the difference between light coming into the left-hand side of the lens and light coming in from the right, which allows the camera to calculate the distance of objects and how to focus on them by assessing the difference between these two perspectives (a process know as phase detection).

The Dual Pixel AF system operates over 80% of the width and height of the sensor, meaning it covers 64% of the image area in total.

Because the left-hand facing pixel halves at the left-hand edge of the sensor can't see through the lens aperture (and vice versa at the other edge), the camera can only use this phase detection system across 80% of the width of the sensor. The image above shows the available, active region of the Dual Pixel AF system.

As noted in the introduction, the EOS M5 is the first M-series camera to fully realize the potential of adapted EF and EF-S lenses - they behave almost exactly as they would on the 80D in Live View, meaning they're far more usable and reliable than with the older 'Hybrid CMOS AF III' system used on the M3 and M10.

The bike test and real-world examples

The Canon EOS M5 basically aced our head-on bike test, so we've put together a sample of the weave test using Canon's 'Face + Tracking' continuous autofocus. The results are broadly positive, with the camera having some struggles as Richard comes around from his weave, which we'd expect. In fact, its performance is a significant step up from what we saw from the EOS 80D in Live View, and while shooting more frames per second to boot. Not too shabby.

Face detection autofocus in stills and video

You'll see more evidence of just how good Canon's face detection can be in the reel on our Video page, but check out this demo. The M5's autofocus system is intelligent enough that, when the camera loses focus on Dan's face, it keeps tracking his head, or exactly where his face used to be. When his face comes back into view, it smoothly recognizes that and continues on. It's remarkable.

Real-world autofocus and performance

For most users, the autofocus and general performance on the EOS M5 will be more than good enough, but it has a few quirks that keep it from being the best mirrorless option in its class for shooting fast action. 

Shooting a victory parade shouldn't be terribly difficult for a camera of this caliber, but the M5 made it a little harder than it needed to be. Shutter blackout (either in the viewfinder or on the screen) is longer than most competitors at this point; it's long enough to be a problem even with subjects moving at modest speeds and at moderate focal lengths. There's a slight delay in the live feed after capturing either single shots or bursts, resulting in the freezing of Touch & Drag AF for that delay. Depending on your 'Touch & Drag' settings, this can cause you to lose your bearings and send your AF point all over the place.

He was much happier about his MLS cup than I was with the EOS M5's blackout and shutter response. Processed and cropped to taste from Raw, EF-M 55-200mm lens at 200mm. ISO 2000, 1/500 sec, F6.3. Photo by Carey Rose

Intentionally half-pressing before shots or keeping the shutter half-pressed between shots will result in the most responsive experience (because focus and exposure are already locked), but if you take your finger off the shutter button and then mash it (perhaps to capture an unexpected moment), you'll be greeted with a solid delay before the camera fires, even if your subject hasn't changed much in depth. Unfortunately, even attempting to circumvent the camera's need to lock focus and exposure by enabling back-button (or manual) focus and shooting in full manual doesn't resolve this issue.

The EOS M5 will occasionally take its sweet time to fire off a frame - and with no provision for focus priority versus release priority, nor any difference in behavior by switching to back-button-focus, the M5 may frustrate you until you adjust to it fully. Processed to taste in Adobe Camera Raw, EF-M 55-200mm F3.5-6.3 lens. ISO 400, 1/320 sec, F6.3. Photo by Carey Rose

It should be noted, though, that overall, the EOS M5 makes for a more responsive live view experience in almost every way than the EOS 80D - right down to the 7fps burst shooting with autofocus (9fps with it locked). An additional caveat when shooting bursts with the M5 is that you're only greeted with a slideshow of the most recently shot image, while many of its mirrorless competitors offer a degree of 'live feed' while shooting bursts that help you track the action.

As far as the EVF, if you lower the camera for a fraction of a second to re-check the action and raise it back to your eye, you'll likely miss a shot due to the delay in switching from the EVF to the screen and back again (I would disable the eye sensor in crucial situations).

Running to catch the tail end of the parade. Processed and cropped to taste in Adobe Camera Raw, Canon EF-M 55-200mm F3.5-6.3. ISO 1000, 1/400 sec, F5.6. Photo by Carey Rose

In terms of more general shooting performance, the EOS M5 is perfectly competent. Startup times hover around a second, and manipulation of settings in more casual shooting is responsive, as is menu operation and playback (but disable the silly playback 'animations' between frames for best performance).

Despite the issues I faced, the EOS M5 is responsive enough under more casual circumstances. Processed and cropped to taste in Adobe Camera Raw. Canon EF 35mm F2 IS USM. ISO 1000, 1/60 sec, F2. Photo by Carey Rose

Card write times are reasonably quick, though the buffer fills quickly - around 2 seconds at 9 fps, and 3 seconds at 7 fps, shooting both Raw and JPEG. While the buffer is clearing (around 7-8 seconds with a SanDisk ExtremePRO 64GB SDXC UHS-3 card), you can change basic shooting settings and resume shooting if you like, but you can't enter playback, the main menu or the Q menu while you wait.

The EOS M5's battery life is rated at a below-average (for the class) 295 shots, though using Eco mode boosts that to 410 by dimming the screen after two seconds of inactivity and shutting it off entirely after 10. The built-in flash used for these tests is sure to hamper the M5, and in real-world shooting, a battery lasts a day of moderate use if you keep the flash and playback viewing to a minimum.