Lock-On Af (On) - Sony DSC-HX400 Help Manual

Menu item details
Off:
Does not track a subject to be focused on.
On:
Tracks a subject to be focused on.
[49] How to Use

Lock-on AF (On)

Maintains the focus on a moving subject automatically.
1. MENU →
2. Align the target frame and the subject to be tracked, and press
Note
The [Lock-on AF] function may not operate 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.
Hint
If you lose track of the subject, this product can detect the subject and resume the Lock-on
AF function when the subject reappears on the screen.
[50] How to Use
Using shooting functions
(Camera Settings) → [Lock-on AF] → [On].
Using shooting functions
Adjusting the focus
Adjusting the focus
in the center.