Custom button map
How do you assign the custom controls on a Nikon Z5 II — and which role does no button on this body get?
The f2 desk
All stills assignments happen at Custom Setting f2. The bench: Fn1 and Fn2 on the front (factory roles: Fn1 white balance, Fn2 Focus mode/AF-area mode, both adjusted by holding the button and turning the command dials), the AF-ON button, the sub-selector center, OK, Playback and DISP buttons, the ISO sensitivity and exposure compensation buttons, the dedicated Picture Control button, the video record button, both command dials, and the lens controls — Lens Fn, Lens Fn2, the Lens Fn ring in both directions, the lens memory set button and the lens control ring. Video assignments live separately at g2 Custom controls, which can also assign the shutter-release button.
An override under your finger
Assign the Fn1 button AF-area mode + AF-ON with a preset of 3D-tracking: holding it swaps in the preset area and starts focus; releasing restores the area previously in effect. Assign Fn2 Switch eyes to choose the other eye when the camera detects a portrait subject. On lenses with the controls, pair Lens Fn2 → Save focus position (hold to store a focus distance) with Lens Fn → Recall focus position (one press returns focus to the stored mark).
No detection button — on any current Nikon here
Subject detection has no assignable role in the f2 or g2 tables on this body: it is switched in [AF/MF subject detection options] in the shooting menus or via the i menu's [AF-area mode/subj. detection] item, which puts AF-area mode and detection on one screen. Set the day's default category in the menus and let the i menu carry mid-shoot changes.
Make the three assignments in f2, then shoot ten frames using the Fn1 override to chase anything that moves across your frame. If white balance was your Fn1 habit, it now lives one press away in the i menu.