Basics

The Exposure Triangle: ISO, Aperture, and Shutter Speed

Master the three pillars of photography to take full control of your images. Stop shooting in Auto mode today.

Sarah Jenkins
2025-02-15
5 min read

The Exposure Triangle Explained


Photography can seem complicated, but it really boils down to three main settings: **ISO**, **Aperture**, and **Shutter Speed**. Together, they form the "Exposure Triangle".


1. Aperture (The Eye)

Aperture controls how much light enters the lens. It also controls **Depth of Field** (how blurry the background is).

  • **Low f-number (f/1.8)**: Lots of light, blurry background (great for portraits).
  • **High f-number (f/16)**: Less light, everything in focus (great for landscapes).

    • 2. Shutter Speed (The Blink)

    Shutter speed controls how long the sensor is exposed to light. It captures or freezes motion.

  • **Fast (1/1000s)**: Freezes action (sports, kids).
  • **Slow (1/30s)**: Blurs motion (waterfalls, night shots).

    • 3. ISO (The Sensitivity)

    ISO is your camera's sensitivity to light.

  • **Low (ISO 100)**: Best quality, needs good light.
  • **High (ISO 3200)**: Grainy/noisy, but lets you shoot in the dark.

    • Putting it Together

    To get a perfect exposure, you need to balance these three. If you increase shutter speed (letting in less light), you might need to open the aperture (letting in more light) to compensate.