AF usability & new system explained

Nikon has made substantial improvements to the Z7's AF system since launch. This page reflects the behavior of the camera using Firmware 3.0, launched in February 2020.

Key Takeaways:

  • AF modes differ from Nikon DSLR's, but have been improved to be more consistent
  • AF points are easily visible
  • AF Tracking needs to be activated from Auto Area mode
  • Auto Area mode tends to prioritize distant subjects, rather than near ones
  • Eye detection works well, though does not always put focus perfectly on the iris
  • A pet face detection mode has been added but we found the camera detects both human and animal faces, regardless of mode

Aufofocus control

The AF system in the Z7 is an evolved version of Nikon DSLR's Live View mode, redesigned to be more consistent with the Nikon's through-the-viewfinder operation.

This has the advantage that the autofocus system is highly consistent between stills and video shooting. And, while we've found it to be less effective than the system on Nikon's DSLRs in through-the-viewfinder shooting, the usability has been improved.

AF Modes:

  • Pinpoint AF (AF-S only)
  • Single Point
  • Dynamic Area (AF-C only)
  • Wide S
  • Wide L
  • Auto

Single point

Dynamic

Dynamic Area is most similar to the 'Dynamic 9' mode on Nikon's DSLRs, while Wide S and Wide L are increasingly larger areas than single point. Wide L ends up being slightly larger than the 'Dynamic' area. As on Nikon's DSLRs the chosen point is always shown in red, to ensure visibility.

When shooting we didn't find the Wide modes especially useful and would much rather have seen a choice of 'Dynamic' mode sizes, or the 'Group AF' as you get on Nikon's DSLRs.

Auto area, Face Detection and Tracking modes

The Auto area makes use of the entire frame and should give emphasis to things nearby and near the center of the frame. It will prioritize faces and eyes if you have face/eye detection enabled.

An arrow appears on the eye/face detection box if the camera has found other eyes or faces in then scene. Pressing left or right on the back of the camera lets you choose between them. You can also tap on the screen to select a face, though this will sometimes use Tracking AF instead. However, since Face/Eye Detection is only available in Auto area mode there's no way of pre-selecting, for instance, the face on the right of your image.

AF Tracking is also part of Auto area mode. It works differently depending on whether you're using the camera's physical controls or holding the camera away from your face and using the touchscreen.

If you tap on the touchscreen, the camera will track the subject you tapped and will continue to do so unless you press cancel on the screen or press the 'Zoom out' button. It will continue to track your subject even if you take a photo, and subsequently

When you release the shutter or AF-On button, the tracking target reverts to your originally chosen position, ready to track a new subject

Alternatively you can press OK or a customized button to enter AF Tracking mode. This places a tracking target box in the center of the screen, which can be re-positioned using the joystick. This box will then follow your subject, when you initiate AF. When you release the shutter or AF-On button, the target reverts to your originally chosen position, ready to track a new subject. This avoids the need to 'cancel' the tracking, which took time and saw the AF point reset to the center.

AF Tracking mode and Face/Eye Detection are distinct, mutually exclusive modes. This means the camera won't recognize and track a face if that's what's under your chosen AF tracking point. However, you don't have to exit Face/Eye tracking mode (which is a multi-option mode, so can't easily be toggled) in order to track a non-face subject within the scene: you can simple engage AF Tracking, which over-rides Face Detection.

Low light AF mode

The Z7 offers a Low-Light AF mode in AF-S shooting. This mode is especially handy for tripod shooting in very dark scenarios - focus speeds are slow, but precise. It can be engaged from within Autofocus custom settings menu.


AF-S usability

AF-S performance is precise and snappy.
ISO 64 | 1/640 sec | F1.8 | Shot with the Nikon Z 35mm F1.8 S
Photo by Dan Bracaglia

AF-S performance is snappy and precise. The 'Single Point' is a nice size for a lot of shooting, and it's bright red so it's always visible.

To make it quicker to move and select an AF point with the joystick or touchscreen, there's an option to limit point selection from 493 points to every alternate point, meaning you only have about a quarter as many points (135) to navigate. Most photographers are likely to find this gives enough locational precision for most shooting.

Pinpoint AF is very precise but can be unusably slow

However, those times you do need a very fine point in a very specific location: a small bird between branches, or a subject's eye (in the absence of any eye-detection system), you'll need to use 'Pinpoint AF'. This is contrast-detection only, so is very precise but prone to hunting. In fact, we found it generally to be unusably slow, both in terms of positioning the point and in that our subject had usually moved before focus was acquired.

The good news is that the AF-S system is otherwise pretty quick, without an obvious speed penalty for its precision-enhancing contrast detection step. Oddly we found some adapted F-mount lenses would focus faster than the initial Z-mount lenses.

We found it would sometimes focus on the background and ignore closer subjects

We didn't have so much luck with Auto area mode. We found it would sometimes focus on the background and ignore closer subjects and we that engaging Face Detection mode made things worse as it would regularly register a 'false positive' and focus on a distant balloon or chair leg.

The experience of selecting between faces ends up feeling like a video game

We also had problems when trying to select between multiple detected faces. All it takes is for one of the subjects to look away and you lose the option to select it. The experience ends up feeling like a video game, trying to hit the arrow key as quickly as the camera provides the option, just it case it disappears again.

AF-C with tracking - usability

Subject tracking, or the ability of the AF system to recognize and follow your chosen subject around the frame no matter where it moves to, can be a very useful feature. It means you can concentrate on composition, not keeping your subject under the focus point. 3D Tracking on Nikon DSLRs is the current gold standard in this regard.

With firmware 3.0, the camera can be made to behave fairly similarly. You need to chose Auto area and then manually engage Tracking AF, either by pressing 'OK' or a custom button, but at that point the camera will track whatever's under your tracking target box. This box can be maintained off-center if you can anticipate where your subject's going to appear, and resets to that position when you release the AF-On or shutter button (whichever is being used to initiate AF).

Tracking mode is disengaged if you go to playback mode, visit the menus or turn the camera off so, unlike 3D Tracking mode on DSLRs, you can't just leave your camera in tracking mode.

Unlike Nikon's DSLRs, you can't set a button to shift to a specific AF area mode and engage AF, so you can't have a button to temporarily engage a different AF mode.

Flash AF Illumination

Our final frustration with the Z7's autofocus behavior is one that's common across mirrorless cameras: the failure to fire the AF illumination lamp on external flashguns. There are some technological reasons for this, but it's still a major drawback for anyone shooting key-moment photographs in low light conditions. Especially with a camera that struggles in low light as much as the Z7.

Click here to find our why we think this is so important.

Conclusion

We're somewhat perplexed as to why Nikon went to the effort of recreating the exact look of some of its AF modes (Single and Dynamic) but not followed through to fully mimic the the behavior of 3D Tracking mode. But, with the advent of firmware 3.0, it's become much quicker to engage AF Tracking mode, and its behavior – resetting to the previously chosen position when you release the shutter or AF-On button – has been made much more usable.

The differences in performance are almost easier to accept, since its live view AF system - even when it underpinned the likes of the Coolpix A's operation - hasn't previously been expected to deliver competitive performance for high speed shooting. But, while performance shortcomings are likely to improve with iteration, it's harder to forgive discarding the experience that had been carefully honed over decades of development and feedback from professionals.