How They Work Together (Triangle Concept)

Imagine a triangle where each point affects exposure:

• Bright image? Increase light from any of the three.
• Dark image? Decrease light from any of the three.
• BUT changing one affects the others:
• Widening aperture lets in more light, so you may need a faster shutter or lower ISO.
• Raising ISO brightens the image, but may introduce noise—so you might stop down the aperture or shorten the shutter time.