AVer DL30 Manuel D'utilisation page 27

Focus
Preset Position
Switch to auto (AF) or manual (MF) focus.
You can configure AF Mode

Camera Settings > Camera Control.
Manual focus: Click the minus sign to focus near and

plus sign to focus far.
 One push focus: Click
focus automatically once.
Select the number to view preset positions. User can also enter
preset position number (0~255) in "Go to" column directly for a
quickly calling section.
18
under Settings (
to adjust lens
) >