Question

A shallow depth of field means that what part of the photo will be in focus?

Answer 1

Depth of field is a zone of acceptable focus before and after the point focused upon. This zone is not split down the middle. As a general rule, this zone extends from the point focused upon, 2/3 away from the camera and 1/3 back towards the camera. The length of the zone is a variable based the camera’s aperture setting. 

Answer 2

Only a small portion that you choose .