Focus Hold

Definition:

Mechanism that freezes the auto-focus adjustment. It is also called `Focus Lock'.

Description:

Mechanism which allows picture taking by stopping the adjustment of auto focus temporarily while fixing the focus status of the photographic lens.

Some mechanisms will fix the focus automatically whether the subject moves or not once the subject is caught in focus, while others will fix the focus, stopping forcibly the autofocus adjustment.

It can be used to advantage when shooting the subject when it is out of the focus detection area of the composition.