Every photograph is a measured amount of light. The exposure triangle is simply the three controls that decide how much light reaches your sensor — and what side effects each one brings.
01Aperture: the size of the opening
Measured in f-stops, aperture controls how wide the lens opens. A low number like f/1.8 lets in lots of light and blurs the background; f/11 keeps more of the scene sharp. Use wide apertures for portraits and narrow ones for landscapes.
02Shutter speed: the length of the moment
A fast shutter (1/1000s) freezes a running dog mid-stride. A slow one (1/15s) blurs motion and invites camera shake. A good handheld rule: keep shutter speed at least 1/focal length.
03ISO: the sensor's sensitivity
Raising ISO brightens the image electronically, at the cost of noise. Modern cameras stay clean up to ISO 3200 or beyond, so don't fear it — a sharp, slightly noisy photo beats a blurry clean one.
04Putting it together
Pick the setting that matters most for your shot first, then balance the other two. Try aperture priority mode for a week — it's the best training wheels in photography.
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Written by
Maya Laurent
Portrait and documentary photographer for 12 years. Maya edits our photography guides and still shoots mostly on a 35mm and a 50mm prime.
