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Exposure / Learn by doing

Exposure Triangle explained simply

What is “Exposure Triangle”?

A way of remembering the relationship between aperture, shutter speed and ISO. Changing one often means adjusting another to keep similar brightness.

  1. 01Aperture: depth
  2. 02Shutter: motion
  3. 03ISO: signal
Visual reminder: Aperture: depth → Shutter: motion → ISO: signal. The illustration is a learning aid; use the practical exercise below to see the effect in a real photograph.

How do you use Exposure Triangle practically?

A small exercise

Start with a still object. Open the aperture by one stop, then shorten the shutter time by one stop. Compare brightness and background sharpness.

  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 Exposure Triangle solve a problem?

It helps you change the look of movement or focus without accidentally making the whole image much brighter.

What can go wrong?

The three controls do different jobs. ISO is not another hole or a longer shutter time.

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?

Aperture: depth → Shutter: motion → ISO: signal. 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

Exposure controls — 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.