Since the debut of the Z System in 2018, Nikon cameras have taken a giant leap forward in terms of autofocus performance. The original Z6 and Z7 models, with which Nikon entered the mirrorless waters, could only detect the eyes of humans, dogs, and cats. And today? Their newest cameras can detect the “eyes” of almost anything that moves, including vehicles. However, relying solely on advanced AF algorithms would be overly optimistic. As good as the subject detection is in modern Nikon Z cameras, there are times when it simply fails. What do you do then?
Unfortunately, these moments are hard to predict. Better subject detection performance doesn’t always correlate to what we think of as “easy” subjects. For example, the average birdwatcher can easily detect a Heron, but a Potoo on its daily perch is quite a challenge even for an experienced birder. Nikon cameras see it differently. Eye detection with the invisible Potoo has proven to be a piece of cake in my experience, while the Heron can sometimes be a problem.
There are a number of other factors that will determine how successful the subject detection will be. First among these is the quantity (and quality) of light. Lens speed also makes a difference – a lens with a maximum aperture of f/2.8 will give the focusing system more flexibility than one with f/6.3. And of course, it also depends on the environment and the position of the subject. Does it blend in too much with the background? Is it partially obscured by vegetation? Is it striking an unusual pose? All of these can contribute to subject detection failures.
Simply put, the situations in which subject detection can go wrong are still quite common. For this reason, it makes sense not to put all your eggs in one basket and to have a backup plan. You need to know how to take control with one of the standard autofocus algorithms and not miss a beat.
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Assigning Focus Modes to Different Buttons
A great feature of today’s Nikon cameras is that you can activate autofocus in many different ways, not just by half-pressing the shutter button. In fact, wildlife photographers are traditionally encouraged to disable half-press autofocus and instead to focus using the AF-On button. But you can take it even further than this.
Namely, it’s not just the AF-On button. You can also assign focus activation to other function buttons, including the buttons that may be found on your lens. You can even assign each of these to activate different autofocus modes. So, for example, pressing AF-On could perform subject detection with Wide Area AF – but pressing Fn1 instead would activate a totally different AF mode, like single-point autofocus.
Of course, the specific autofocus modes are up to you. My preference is to dedicate the camera’s main AF-On button to Nikon’s subject tracking autofocus (specifically, with a custom sized Wide Area AF box). Then, I dedicate the Fn1 button to Dynamic Area AF (Small), which lacks subject recognition and lets me pinpoint the subject a little more if the automatic recognition fails.
Assigning these custom function buttons is as easy as going into the Custom Control Assignment option in Nikon’s menu.
How to Assign Each Button
Every person has their own taste in music, and every photographer has their own taste in camera setup. I don’t want to presume that how I set up my cameras is exactly how you should set up yours. However, I think that it provides a good starting point for sports and wildlife photographers who want to assign different focus modes to different buttons.
On my Nikon Z9, it looks like this. Most importantly, I’ve assigned both the AF-ON button and the DISP button to subject recognition with Wide Area AF modes. The only difference is the size of the boxes. Then, on the front of the camera, I’ve assigned Fn1 to Dynamic Area AF (Small) to let me pinpoint my subject when subject recognition fails. I prefer to leave the shutter button free from activating autofocus, because there are times when I want to take a photo without autofocus engaging.
I recognize that my camera, the Nikon Z9, has a lot more custom function buttons than other Nikon Z cameras. But even if you only have a couple of customizable buttons, I believe that assigning them to different autofocus modes is worthwhile, at least for wildlife photography. Here, for example, is how you could assign it for the Nikon Zf:
Unfortunately, not all Nikon Z cameras allow you to change the AF mode and activate autofocus simultaneously, like the Z9 does. If your camera offers this feature, it will be called “AF-area mode / AF-On” and will be located in the Custom Control Assignment section of the Custom Setting Menu.
However, all Nikon Z cameras do at least allow you to assign the custom buttons to select AF mode. This is much better than going into a menu for them, like some Z cameras want you to do. It still isn’t as convenient as immediately engaging autofocus when you press the button, but at least it lets you take control quickly when subject recognition fails. Again, all of this customization can be found in the Custom Control Assignment section of the Custom Setting Menu.
AF on the Lens Buttons
Some Nikon Z lenses offer a wide range of possibilities for using the function buttons on the lens. Among other things, they can be used for focusing. The buttons on the lens can be particularly useful if you do not have the appropriate buttons on the camera body, or if this option suits you ergonomically. You can assign the buttons the following functions:
- AF-ON: These duplicate the function of the AF-ON button on the back of the camera (or the shutter button if you use it to focus)
- AF-area mode: If you press and hold this button, the AF mode will change to Single-point AF or Dynamic-area AF, for example. However, you will still need to use the camera’s AF-ON button (or shutter-release button) to activate autofocus.
- AF-area mode + AF-ON: This mode combines both AF mode switching and AF activation. It is my preferred approach.
Conclusion
No tool is universal. Not in your garage, your kitchen, nor your camera. Although automatic subject detection is a powerful tool, it is not a one-size-fits-all solution. When it fails, it’s best to fall back on a “dumb” autofocus algorithm, ideally with a much smaller autofocus box, so that you don’t miss a moment in the field. By setting up your Nikon Z camera ahead of time to prepare for this possibility, you won’t lose a step any time that subject recognition fails.
I hope this article gave you some good ideas. If any of your questions remain unanswered, feel free to ask me in the comments below the article.
