What is the exposure triangle?
The exposure triangle describes the three settings that control image brightness: aperture, shutter speed, and ISO. These three are interconnected — changing one requires adjusting at least one of the others to maintain the same exposure.
The three sides of the triangle
Aperture (f-stop): Controls how much light the lens lets in. Wider (f/1.8) = more light + shallower depth of field. Narrower (f/8) = less light + deeper focus.
Shutter speed: Controls how long the sensor is exposed. Faster (1/1000s) = less light + freezes motion. Slower (1/30s) = more light + motion blur.
ISO: Controls sensitivity. Low (100) = clean image + needs more light. High (6400) = noisy image + works in darkness.
How they work together
Imagine shooting indoors and the image is too dark at f/4, 1/60s, ISO 400. You have three options:
Open the aperture to f/2.8 — 2x more light but shallower depth of field.
Slow the shutter to 1/30s — 2x more light but risks motion blur.
Raise the ISO to 800 — brighter image but adds noise.
Understanding the tradeoffs lets you make the right choice for each situation.
Cameras for learning at Camera Shop Egypt
Which setting to prioritize
For portraits: Set aperture first for desired depth of field, adjust the rest.
For sports: Set shutter speed first (fast enough to freeze motion), adjust the rest.
For video: Set shutter speed to double your frame rate (180-degree rule), adjust the rest.
For landscapes: Set aperture first (f/8-f/11), use a tripod for slow shutters, keep ISO low.
Start in aperture priority mode (A or Av). Set the aperture you want, let the camera choose shutter speed and ISO. This is how most professionals shoot 80% of the time.