Pull focus, also called rack focus, is a cinematographic technique where the camera's focus point is deliberately shifted during a shot from one subject or depth plane to another, causing one element to move from sharp clarity into blur while another transitions from soft to sharp. The technique directs the viewer's attention with precision, using focus as a storytelling tool rather than simply maintaining everything in the frame at consistent sharpness.

The technique requires manual or electronically controlled focus adjustment timed to the action or editorial intention of the scene. A classic example is a shot where a character in the foreground is initially in sharp focus while another person behind them is soft; as the scene develops, focus pulls to the background figure, shifting narrative emphasis. Pull focus can also be used to reveal previously unnoticed elements, create a sense of dramatic weight around a moment of realization, or build suspense by directing attention away from and then back to a key subject. The shallow depth of field required for an effective pull focus is achieved with wide aperture settings and longer focal lengths, which is why the technique is more commonly associated with cinematographic lenses than wide-angle smartphone footage.

When prompting AI video generation for pull focus effects, describing the before-and-after state of the focus shift helps communicate the intended result. Phrases like "rack focus from foreground figure to background subject," "pull focus reveal from blurred subject to sharp," or "shallow depth of field focus shift" can guide generation toward this technique, though the precision of in-shot focus transitions varies across different video generation tools.