Autofocus

Out of camera JPEG.
ISO 100 | 1/125 sec | F13 | Shot on on the Canon 18-135mm 3.5-5.6 @ 135mm
Photo by Carey Rose

The 90D's live view Dual Pixel autofocus is more reliable than its conventional through-the-viewfinder phase-detection system. The spread of AF points in live view is also far greater than the 45-point spread of the traditional AF system, however you'll still get faster bursts shooting through the finder.

Key takeaways:

  • AF performance is considerably more reliable in live view than through the finder, but the burst rate is 3 fps slower
  • Super-sticky Face and eye detection in live view (stills and video)
  • Through-the-viewfinder AF reliability lags behind DSLR competition

Autofocus

AF overview

Through the finder AF modes

AF area modes when shooting through the finder include (left to right): Spot (new), 1-point, Zone, Large Zone and Auto Selection area.

Live view AF modes

AF modes in live view include (left to right): Face+Tracking, Spot (new), 1-point and Zone.

The 90D uses two separate autofocus systems, depending on whether you're shooting through the viewfinder or using live view. For the former, the camera employees a 45-point point, all cross-type system that's not too different than the system found in the 80D. When shooting lenses stopped down to F8 or smaller you only get 27 points (nine of which are cross-type). By 2019 standards, the spread and number of points feels a little limited. However a new higher-res metering sensor (220,000 pixels, up from 7,560) used for subject recognition, allows for face detection when shooting through the finder, something not offered on the 80D.

The AF spread and number of points is comparably much greater In live view. The 90D uses Canon's Dual Pixel autofocus with Dual Pixels covering nearly 100% of the vertical frame and 88% of the horizontal with up to 5000 points to chose from. Live view also gains an eye detect feature.

Customizing AF

By default the 90D will automatically select what it initially focuses on in 'Auto Area' mode (through the finder) or in 'Face Detect + Tracking' mode (live view). If you prefer to manually select your initial subject via a focus point, head to page 11 of the AF custom function menu (shown above), and select option no.1.

High-end Canon cameras offer a dedicated autofocus menu with scenario-specific options that can be adjusted depending on what you're shooting. Unfortunately the 90D's AF adjustments, located within the camera's confusing and unorganized Custom Function menu, are not scenario-specific and worse, they are far from straightforward. Canon has included an 'info' tab for each option to explain exactly what will be adjusted. But the wording can be pretty confusing.

For testing, we left most options at their defaults, but with some trial and error you may find adjusting them improves your hit rate. One option that we did adjust was the camera's default behavior when using 'Auto Area' through-the-finder or 'Face Detect + Tracking' in live view (C.Fn 11). By default, the camera will automatically select a subject in either of these modes, generally the nearest face or subject in the scene. But this can be changed so that you can manually choose your starting subject via a focus point.

AF performance

AF speed through the finder

Our straight-on bike tests looks at how well a camera can maintain focus on a subject rapidly approaching, using a single autofocus point. All of our bike tests were done using a Canon 70-200mm F2.8 lens at 200mm equiv. (135mm on APS-C) and at the camera's top burst speed, using default AF settings (with the exception of the one noted above). First up we tested through-the-viewfinder AF at 10 fps.

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The results of this test are not particularly encouraging. The 90D consistently falls behind the plane of focus, only to catch up a few frames later. These results are pretty much identical to the 80D.

AF speed live view

We then ran the same test in live view, which offers a burst rate of 7 fps.

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These results are much more encouraging than our previous example. Nearly every frame ended up either in-focus or very close to in-focus.

AF Tracking through the finder

Next up we tested the camera's ability to both maintain focus on a subject approaching while also tracking that subject as they move within the frame. Canon updated its metering sensor in the 90D with greater resolution compared to the 80D. As such, seeing as the metering sensor is used for image recognition, we expected the 90D to do better than the 80D when it comes to through-the-finder AF tracking, but...

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The hit rate was similar to the 80D: mediocre. The camera doesn't reliably stay locked on to, or continuously focus on, our subject. We've seen this before for through-the-viewfinder autofocus on nearly every Canon DSLR, albeit to varying degrees, so this isn't too surprising.

AF Tracking live view

Finally we ran the same test, but in live view. Again the live view burst rate is 7 fps vs 10 fps through the finder.

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And again, the hit rate here is very good, with the majority of images in- or nearly in-focus. And although it's 3 fps slower, you still get more in-focus images than when shooting through the finder at 10 fps.

Face/Eye detect: live view

Canon's live view eye detect is impressive. Lightly processed to taste in ACR.
ISO 500 | 1/500 sec | F1.4 | Canon L 35mm F1.4

In live view mode the 90D's 'Face+Tracking' mode now has eye detection and in our qualitative testing, it's proven exceptionally sticky. The camera seamlessly transitions from eye detection to face detection to a flurry of points and back again when a subject turns their head or becomes briefly obstructed. Though not quite as pin point accurate as say, a Sony's Eye AF, an industry benchmark, the 90D's 'Face+tracking' mode with eye detect is highly usable.

If multiple faces are detected in a scene, the 90D prioritizes the nearest one, but will indicate the presence of others via a small arrow on either side of the face detect box. A quick bump of the AF joystick or D-pad will allow you to jump to a different face and track it. On occasion though, we have found Canon's system to jump between faces in a scene.

One thing to note, if you do switch the initial focus in 'Face+Tracking' mode from 'Auto' to a manually selected point, the camera will generally prioritize the face beneath your starting point. If there is no face under your AF point, the camera will just focus on and track that object. This is a good thing, as it allows you to use the 'Face+Tracking' mode for many different types of photography.

Face detect: through the finder

As mentioned, Canon also added face detection when shooting through-the-viewfinder. It does a decent job finding faces, but with only 45 points to work with, it's not nearly as precise or accurate as Face Detect in live view. Also there's no easy way to jump between faces if multiple faces are present. If no face is detected the camera will instead focus on whatever is nearest.

And similar to live view, if you've set your initial focus in 'Auto Area' from 'Auto' to a manually selected point, the camera will generally prioritize focus on whatever is under the point (be it a face or not), rather than prioritize a face somewhere else in the scene, as 'Auto' does.