Exposure Calculator
Choose which setting you want to solve for, enter the other two values, and get the correct exposure instantly. The calculator also shows you equivalent exposures. These are different combinations of aperture, shutter speed, and ISO that produce the same brightness.
Equivalent Exposures
Same brightness, different look. Each row below gives you the same exposure as your settings above, but with a different trade-off between depth of field, motion blur, and image noise.
| Aperture | Shutter | ISO | Trade-off |
|---|---|---|---|
How the Exposure Triangle Works
Photography comes down to light. That's it. And your camera gives you exactly three ways to control it: aperture, shutter speed, and ISO.
These three settings make up what photographers call the exposure triangle. Change one, and you'll need to adjust at least one of the others to keep your exposure balanced. Once this clicks for you, everything about shooting in manual mode starts to make sense.
Aperture (f-stop)
Aperture is the size of the opening inside your lens. A wider opening (like f/1.8 or f/2.8) floods the sensor with light and gives you that creamy, blurred-out background portrait photographers love.
Go the other way, to something like f/11 or f/16, and you get less light but much more of the scene in sharp focus. That's your go-to for landscapes.
Here's the key thing to remember: each full stop change in aperture (say, f/2.8 to f/4) halves the light hitting your sensor. Go from f/4 back to f/2.8 and it doubles. Simple as that.
Shutter Speed
Shutter speed is how long your sensor stays exposed to light. A fast shutter speed like 1/1000s freezes a sprinter mid-stride, a bird in flight, a splash of water. A slow shutter speed like 1/30s or longer lets in more light, but anything moving will blur.
Sometimes that blur is a problem. Sometimes it's the whole point. Silky waterfalls, streaking car lights, dreamy long exposures? All slow shutter speeds.
If you're shooting handheld, a useful rule of thumb: keep your shutter speed at 1/(your focal length) or faster. Shooting at 50mm? Stay at 1/50s or quicker to avoid camera shake.
ISO
ISO controls how sensitive your sensor is to whatever light it receives. At ISO 100 or 200, you get the cleanest, smoothest image quality. Crank it up to 1600, 3200, or beyond, and you'll brighten the image, but you'll also start introducing grain and noise.
Modern cameras are remarkably good at high ISO. But the cleanest results still come from keeping it as low as you can.
Think of ISO as your safety valve. Set your aperture and shutter speed for the look you want first, then bump the ISO just enough to get a proper exposure.
What Is an Exposure Value (EV)?
Exposure Value is a single number that describes a combination of aperture and shutter speed at ISO 100. An EV of 0 means f/1.0 at 1 second. Each step up by 1 EV halves the light, which is one stop.
To give you a sense of scale: bright sunlight is around EV 15. A dimly lit room? More like EV 5 to 7. That's a huge difference in light.
The EV number in this calculator is there to help you gauge how bright your scene is and quickly compare lighting conditions.
What Are Equivalent Exposures?
This is where things get fun. Equivalent exposures are different combinations of aperture, shutter speed, and ISO that all produce the same brightness.
Say you're at f/2.8, 1/250s, ISO 400. You could also shoot at f/5.6, 1/60s, ISO 400 and get an identical exposure. The aperture got smaller (less light in), the shutter got slower (more light in), and those two changes cancel each other out perfectly.
So why does this matter? Because while the brightness stays the same, the look of your photo changes completely. A wider aperture blurs the background. A slower shutter shows motion. A higher ISO adds grain. Same light, totally different photo.
Understanding this is honestly what separates someone shooting on auto from someone who's choosing their settings with intention.