This is a quick step-by-step guide for enabling back button focus on the Nikon Z8.
Or, more precisely, only back button focus. That’s because, by default, the Nikon Z8 does autofocus with either a shutter half-press or the AF-ON button on the back. That is, they’re both enabled by default.
But many photographers (me included) prefer to make it ONLY back button focus, effectively removing autofocus from the shutter button.
I don’t like the way that pressing the shutter button can ruin the focus point when reframing the shot. Or I might be taking photos of a subject that moves slightly but is still staying with a specific focus range; think a baseball pitcher or some situations with wildlife. And with my preference for fast prime lenses and shooting them wide open, with a very narrow depth of field, I want a lot of control over where focus is, and I want it to stay put.
How to Enable Back Button (Only) Auto Focus on the Nikon Z8
The specific setting you want here isn’t as obvious as it could be. You want the setting:
CUSTOM SETTINGS MENU (the pencil) > a Focus > a6 AF activation
Once you get to that, you’ll find the options:
- AF-ON only
The Shutter/AF-ON button option is the default setting. This means that both the shutter button and the AF-ON button can activate autofocus.
To change it to ONLY the AF-ON button, simply select that option.
But there’s a little wrinkle here. When you change it to AF-ON only, there’s actually another set of options below that. But it’s not very obvious; I’m not sure why Nikon has not included a right arrow for this item, which would make it clearer. But they do include a small Select icon at the bottom right.
The sub-options related to Out-of-focus release options. Basically, this determines whether the camera will still take a photo even if focus hasn’t been established.
- ENABLE: This means that a full press of the shutter will take a photo regardless of whether or not focus has been established. This is also known as release priority. I find it especially useful for fast-moving action shots.
- DISABLE: This means that pressing the shutter will only actually take a photo if focus has been established. I find this best for situations where focus is easier to establish but crucially important. For instance, an out-of-focus portrait photo is probably going to be unusable, but you likely have plenty of opportunity for the camera to lock focus. This option is also known as focus priority.
Taking it a Step Further
The typical back-button focus button to use is the AF-ON button. That’s well-positioned to use with your right thumb when you’re holding the camera. And to me, it feels the most natural.
But it’s also possible to assign AF-ON to a different button such as the DISP button or the joystick (aka sub-selector).
To do that, use the Custom controls settings. That’s beyond the scope of this quick guide, but the gist is that you can assign the controls at:
CUSTOM SETTINGS MENU > f Controls > f2 Custom controls (shooting)
If you’d prefer a visual walk-through, I’ve put together this quick video guide to go along with this:
Things Worth Knowing
If you’re using the MB-N12 grip, it also has an AF-ON button, and the setting you assign in the process above also applies to the grip (i.e., you don’t set that separately).