Lenses & focus / Learn by doing
Crop Factor explained simply
What is “Crop Factor”?
A comparison between a camera’s sensor size and a reference format, usually full frame. It helps compare angle of view.
- 01Sensor size
- 02Angle-of-view comparison
- 03Focal length stays fixed
How do you use Crop Factor practically?
A small exercise
Compare a 35mm lens on a 1.5× crop camera with about 52mm on full frame from the same position.
- 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 Crop Factor solve a problem?
It helps choose a lens that gives the view you expect when changing camera formats.
What can go wrong?
Crop factor does not physically change the lens focal length. Exposure f-number is not simply multiplied for metering.
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?
Sensor size → Angle-of-view comparison → Focal length stays fixed. 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
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