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Lenses & focus / Learn by doing

Focal Length explained simply

What is “Focal Length”?

A lens measurement in millimetres that helps describe its angle of view. On the same sensor, a shorter focal length shows more of the scene.

  1. 01Shorter: wider view
  2. 02Longer: narrower view
  3. 03Same camera position
Visual reminder: Shorter: wider view → Longer: narrower view → Same camera position. The illustration is a learning aid; use the practical exercise below to see the effect in a real photograph.

How do you use Focal Length practically?

A small exercise

Photograph a still object at 24mm and 70mm from the same position. Compare how much of the surroundings appears.

  1. Make a starting version and keep it so you can compare fairly.
  2. Try the change in the exercise. Keep unrelated choices steady where the exercise allows.
  3. Compare the result at the size your viewer will actually see. Write down what changed and whether it helped.

How does Focal Length solve a problem?

Choosing focal length helps fit a group into the frame or isolate a distant detail.

What can go wrong?

Perspective changes when you change camera position. A focal length alone does not move the background.

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?

Shorter: wider view → Longer: narrower view → Same camera position. 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

Lens basics — 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.