Sony ILCA-99M2 - Manual (Page 278)

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:
[Sweep Panorama]
When [Smart Telecon.] is being used.
When shooting in Manual Focus mode.
When [
Record Setting] is set to [120p]/[100p].
[290] List of MENU items Camera Settings1
AF drive speed (still image)
Selects the focusing speed when using autofocus in the still image mode.
Menu item details
Fast:
Sets the AF drive speed to fast.
Slow:
Sets the AF drive speed to slow. This setting makes it easier to focus during macro shooting,
etc.
[291] List of MENU items Camera Settings1
AF Track Sens (still image)
You can select the AF track sensitivity when the subject goes out of focus in still image mode.
Menu item details
5(Responsive) / 4 / 3(Standard) / 2 / 1(Locked on):
Select [5(Responsive)] to focus responsively on subjects at different distances.
MENU
→
(Camera Settings1)
→ [
AF drive speed]
→ desired setting.
1
MENU
→
(Camera Settings1)
→ [
AF Track Sens]
→ desired setting.
1