Exposure Triangle Simulator: Aperture, Shutter & ISO

Exposure Triangle

Aperture f/8

Shutter speed 1/125 s

ISO 100

Focus distance 4.5 m

Presets

Readouts

Exposure meter

0.0 EV — correct

In-focus range (depth of field)

3.6 m – 6.1 m

Sensor noise

Blur sweep

14°

How it works

The scene's brightness is fixed; the three exposure controls trade light against each other by the reciprocity law — doubling any one halves the light captured by the sensor, so a correctly-exposed shot has many equivalent (N, t, ISO) combinations.

Exposure value:   EV = log2(N² / t)
Stops from ref:   ΔEV = EV(f/8, 1/125s) − EV(N, t) + log2(ISO/100)
Circle of confusion (thin lens, focal length f):
  c = f² · |S − D| / (N · S · (D − f))
Hyperfocal:       H = f²/(N·c₀) + f
Near/far focus:   Dn = D(H−f)/(H+D−2f),  Df = DH/(H−D)

Where N is the f-number, t the shutter time in seconds, S the distance to an object, D the focus distance, and c₀ a fixed circle-of-confusion tolerance (0.03 mm, the standard full-frame criterion for "acceptably sharp").

Aperture (f-number) — a smaller N means a physically wider lens opening: more light per second, but a shallower depth of field (the cyan focus plane's sharp zone shrinks).
Shutter speed — longer exposure times let in more light but integrate more of a moving subject's path, lengthening the motion-blur trail on the spinning arm.
ISO — electronic sensor gain: it does not add real light, it amplifies what little was captured, which is why raising it also amplifies noise (the grain overlay).
Exposure meter — compares your (N, t, ISO) combination against a fixed reference exposure (f/8, 1/125 s, ISO 100) that is correctly exposed for this scene's luminance.

Focus plane In-focus zone

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