Lenses & focus / Learn by doing
Back-button Focus explained simply
What is “Back-button Focus”?
Assigning focus to a rear button so it can be controlled separately from the shutter release.
- 01Rear button focuses
- 02Release to hold
- 03Shutter takes photo
How do you use Back-button Focus practically?
A small exercise
Set the control using your camera manual. Focus a still subject with the rear button, release it, then take a frame without refocusing.
- Make a starting version and keep it so you can compare fairly.
- Try the change in the exercise. Keep unrelated choices steady where the exercise allows.
- Compare the result at the size your viewer will actually see. Write down what changed and whether it helped.
How does Back-button Focus solve a problem?
It lets you decide when focus updates while the shutter button handles taking the photograph.
What can go wrong?
It is a workflow choice, not an automatic improvement. Explain the setup before someone else uses your camera.
How do you turn the idea into a useful solution?
Start with the specific problem in your image or brief, try the exercise, and keep the version that meets that need. If the result is worse, return to the starting version and change one choice at a time.
Quick check: can you explain the three ideas in the diagram?
Rear button focuses → Release to hold → Shutter takes photo. Explain how each relates to the exercise. Then compare the starting version with your result and choose the one that meets your brief.
Related video lesson
Autofocus lesson — Canon
This related lesson gives wider context for the topic. Camera menus and software versions may differ from yours.
Loading the player connects to YouTube. You can also watch the lesson on YouTube.Keep exploring
Try the idea in a studio shoot
Planning a portrait or product session? Use the glossary with our practical shoot guides, then check the studio facilities and send your confirmed requirements with an availability enquiry.