📷 The Exposure Triangle

Master Aperture, Shutter Speed & ISO

What is the Exposure Triangle?

The exposure triangle is the foundation of photography. It consists of three elements that work together to control how much light reaches your camera sensor:

  • Aperture (f-stop) - The size of the lens opening
  • Shutter Speed - How long the shutter stays open
  • ISO - The sensor's sensitivity to light

When you adjust one element, you often need to adjust another to maintain proper exposure. Understanding this relationship is key to creative photography!

📸 Aperture (f-stop)

What it does: Controls the size of the lens opening that lets light in, like the pupil of your eye.

Key Points:
  • Wide aperture (small f-number like f/2.8) = More light, shallow depth of field (blurred background)
  • Narrow aperture (large f-number like f/16) = Less light, deep depth of field (everything in focus)
Creative Uses:

Portraits: Use f/2.8 or f/4 to blur the background and make your subject stand out

Landscapes: Use f/11 or f/16 to keep everything from foreground to background sharp

⚡ Shutter Speed

What it does: Controls how long the camera's shutter stays open to let light hit the sensor.

Key Points:
  • Fast shutter speed (like 1/1000s) = Freezes motion, less light
  • Slow shutter speed (like 1/30s) = Captures motion blur, more light
  • Handholding rule: Use at least 1/60s to avoid camera shake
Creative Uses:

Action/Sports: Use 1/500s or faster to freeze movement

Waterfalls: Use slow speeds (1/4s - 2s with tripod) for silky smooth water

🔆 ISO

What it does: Controls how sensitive your camera sensor is to light.

Key Points:
  • Low ISO (like ISO 200) = Less sensitive, cleaner images, less noise
  • High ISO (like ISO 1600) = More sensitive, grainier images, more noise
  • Best practice: Use the lowest ISO possible for the conditions
When to Use:

Bright daylight: ISO 200 for cleanest images

Indoor/Low light: Increase to ISO 800-1600 when you need faster shutter speeds

💡 How They Work Together:

The three elements balance each other. When you change one, you often need to adjust another:

  • Opening aperture (f/8 to f/4) = doubles the light → need faster shutter speed
  • Increasing ISO (200 to 400) = doubles sensitivity → can use faster shutter speed
  • Slowing shutter speed (1/250s to 1/125s) = doubles light → can close aperture more

✏️ Practice Questions

Test your knowledge of the exposure triangle! Each time you click "New Questions", you'll get a fresh set of scenarios to solve.