Free course · Camera foundations · Chapter 4

Focus & Background Blur

Choose what should look sharp. Change the aperture and see a simple blur cue. This is a teaching illustration, not a physical lens calculator.

AI-generated illustrative example
A film student in sharp focus in front of a softly blurred interior film set.
This realistic-looking image helps you picture shallow focus. It is an AI illustration, not a measured camera test. Use the interactive scene below to explore focus target and aperture.

See where the focus falls

Actor focus. The actor is the sharpest part of the scene.

Focus: ActorAperture: f/2.8

Adjust the shot

Choose focus target

A lower f-number is a wider aperture and often gives shallower focus.

VFX Supervisor's Note: Agree on focus target and planned focus pulls. Keep the actor's eyes and CG area in mind; report lens or focus changes to the VFX team.

Try it: reveal a CG background sign

An actor stands in front of a sign that will be replaced with a CG sign. Choose where the audience should look first.

Quick check answers

Focus selects the distance that appears sharpest. f/2 is a wider aperture than f/11. A focus pull is a planned change from one focus distance to another.

The blur is intentionally simplified to teach the idea. Real depth of field depends on the lens, aperture, sensor, focus distance, framing, and viewing conditions.