Exposure / Learn by doing
ISO explained simply
What is “ISO”?
A camera setting that changes how strongly the recorded signal is used to make the picture. Higher ISO can help make a usable exposure in low light.
- 01ISO 100
- 02ISO 1600
- 03Compare dark areas
How do you use ISO practically?
A small exercise
Photograph the same scene at ISO 100 and ISO 1600, adjusting shutter speed to maintain brightness. Compare shadow detail at full size.
- 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 ISO solve a problem?
Raising ISO can let you use a faster shutter when a person keeps moving in a dim room.
What can go wrong?
ISO does not add light to the scene. Noise depends on the light captured, camera and processing as well as the ISO setting.
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?
ISO 100 → ISO 1600 → Compare dark areas. 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.