Pull Focus

Pulling Focus (or follow focus) is performed by changing the focal point within the depth of field to keep the same object of interest in focus (if it is moving), or to move the focus point from one object to another.

Fig #1

This shows how different objects in the shot

can be brought in to focus.

When film makers need to use this technique, they often need an additional member of the film crew (called the Focus Puller) to assist the main camera operator.  The Focus Puller will concentrate on keeping the correct focal point, whist the camera operator would be in charge of moving the camera and starting/stopping the filming.

Fig #2

The Focus Puller in action.

A great example of how to pull focus can be seen in the YouTube video below:

Fig #3

How to Pull Focus

From '60 Seconds on Set'