Sony Cyber-shot RX10 III - Manual (Page 89)

Functions assigned to the control wheel or [Custom Button 3] cannot be executed while
the focus range finder frame is being moved.
The position of the focus range finder frame cannot be changed during movie shooting.
[68] How to Use Using shooting functions Adjusting the focus
Center Lock-on AF
When you press the center button, the camera detects the subject positioned in the center of
the screen and continues to track the subject.
1. MENU
→
(Camera Settings
) → [Center Lock-on AF] → [On].
2. Align the target frame (A) over the subject and press in the center of the control
wheel.
Press again to stop tracking.
If the camera loses track of the subject, it can detect when the subject reappears on
the monitor and resume tracking.
3. Press the shutter button fully down to shoot the image.
Note
[Center Lock-on AF] may not function very well in the following situations:
The subject is moving too quickly.
The subject is too small, or too large.
The contrast between the subject and the background is poor.
It is dark.
The ambient light changes.
Lock-on AF does not work in the following situations:
In [Sweep Panorama] mode
When [Scene Selection] is set to [Hand-held Twilight] or [Anti Motion Blur].