Autofocus

The cornerstone of the D500's appeal is its autofocus system. Sure it has: 153 points, 99 of which are cross type, 15 of which will work with f/8 maximum aperture lens+teleconverter combinations, which will work down to -3EV (-4EV for the center point), but that's not a very helpful way of looking at it.

Instead it's arguably better understood as having the latest version of Nikon's pro-level AF system, with the added bonus of having its points spread out across most of the viewfinder, since the camera uses the smaller APS-C format.

The AF system offers coverage across most of the width of the frame and, with most F4 or faster lenses, includes more accurate and reliable cross-type points down the edges.

This also means the 3D Tracking system can follow a subject almost anywhere in the scene. Alternatively, instead of focus-and-recomposing, you can set focus point and recompose, meaning no risk of focus shift or your subject moving.

This wide spread of cross-type AF points yields faster, more decisive focus in more challenging light - such as backlit or low light situations where subject contrast is low, since it has two axes of detail to assess.

Interestingly, Nikon says that the full capabilities of the system are only available with AF-S lenses. The number and spread of available cross-type points is reduced not only by combinations with smaller maximum apertures, but also with older lenses and a handful of AF-S.

AF area modes

As you'd expect from a pro-derived AF system, the D500 offers a broad range of AF area selection modes, from manually specifying a single point up to letting the camera pick an autofocus area automatically:

  • Single point - You choose one of the 55 selectable AF points, using the joystick 
  • x-point Dynamic Area - You select a single AF point, but the camera will consider x points around it if the subject temporarily strays off the selected point (with a choice of 25, 72 or 153 points).
  • Group Area AF - You select a group of points and the camera prioritizes what it thinks is the subject within that area (Nikon advises its use for subjects that are difficult to keep a single point on, to prevent the camera jumping focus to the background). Equal priority is given to all points.
  • 3D Tracking - You manually select the initial AF point and the camera then attempts to track the subject under that point as it moves around the frame, using other AF points as necessary. The D500 lets you choose whether 3D Tracking should include Face Detection. Turning this on sees the camera prioritize faces near your selected AF point over other objects. The AF area also appears to become a little more jumpy - following faces better but feeling less certain when pointed at non-human subjects.
  • Auto Area - the camera selects a focus point or group of points automatically, largely based on how close it is (possibly with weighting towards the center of the frame). This area mode prioritizes detected faces.

Configuration

Traditionally, Nikon has only provided a single setting to define the system's persistence before it re-focuses on a subject at a different distance. The D500 now gains another setting to specify how predictable the subject's speed and acceleration are (essentially whether the camera should refocus assuming the subject won't suddenly stop).

Rather than offering different use-case based presets as Canon does (for its 3-variable fine-tuning) Nikon's NPS pro support service offers advice for the settings that best suit a range of sports. It's interesting to note that NPS suggest using dynamic area AF modes for most situations, rather than 3D Tracking - something we looked at when shooting with the camera.

Performance

In circumstances where there is a clear subject, well isolated from the background, the D500's autofocus and tracking is hugely impressive. Even in circumstances where it only has a fraction of a second to acquire both the subject and focus, it does very well indeed, rendering our bike test irrelevant. Our test is designed to simulate a subject moving unpredictably at a moderate speed (such as a small child running towards the camera) and this presents no challenge at all for the D500, even when the camera is chattering away at 10 fps.

In this instance, the rider started off too far back for us to be able to specify that the camera should focus on his face, so instead it's focused on his shirt, but the consistency between shots is excellent. We shot the same test multiple times (generating over 700 images) and found we could pick images at random and be supremely confident that they'd be in focus.

Team Sports

Given how well it performed in our standard test, we decided to check just how much of the D5's capability you get in the D500 and made sure we shot a variety of fast-action activities to see what it's capable of.

For skateboarding, BMX and motorsport, 3D Tracking did very well - very quickly acquiring focus on the subject under our AF point and then following it even during burst shooting. However, it's notable that all these events feature a single subject that's fairly distinct from its background, both in terms of depth and color (the two parameters the camera can interpret).

Polo and soccer proved more challenging for 3D Tracking. With multiple similarly-attired subjects we found that, while generally very good, the camera could be distracted too often to be depended on. Even with some adjustment of the 'Blocked Shot Response,' the camera would occasionally wander off and follow a different player if they stepped in front of the intended target.

In the end, my preferred way of working ended up being to put the camera in 3D Tracking mode, with 25 point Dynamic AF mode on the AF-On button. In addition, I engaged 'Store by Orientation' so that the camera remembers a different AF point depending on which way up I was holding the camera. This way I could let the 3D Tracking point follow the action around the scene but then hammer on the AF-On button when other players encroached on the action. Letting go of that AF-On button then re-engaged subject tracking, as long as the shutter was still half-depressed. Switching between the two modes instantaneously was a new, and useful way of working.

None of the camera's capabilities suddenly made me into a great sports photographer but I definitely left with the sense that most of the improvements there to be made were in my technique, not the camera's capability.