Studio Lighting Setup: Three-Point Lighting Lab

Lighting Patterns

Key Light

Azimuth (around subject) 35°

Elevation (height) 45°

Distance 3.0 m

Softbox size (softness) 50%

Fill & Rim

Fill ratio (vs. key) 25%

Rim / hair light 30%

Live Readout

Key illuminance

0 lx

Fill illuminance

0 lx

Lighting ratio (key : fill)

1.0 : 1 (0.0 stops)

How it works

Every light on a studio rig obeys the inverse-square law: illuminance falls off with the square of the distance from source to subject.

E = I / d²
E   = illuminance at the subject (lux)
I   = luminous intensity of the source (candela)
d   = source-to-subject distance (m)

The key light sets the exposure; the fill light lifts the shadow side. Photographers describe the contrast between them as the lighting ratio, measured in stops (each stop = a doubling of light):

ratio (stops) = log2(E_key / E_fill)

A small, distant source acts like a point light and casts a hard-edged shadow. A large source close to the subject — a softbox — subtends a wider angle from the subject's point of view, so the shadow's penumbra (transition zone) widens and the edge goes soft. That's why the "Softbox size" slider drives both the rendered penumbra and the visible size of the light panel in the scene.

Butterfly / Paramount — key almost on-axis, high overhead: a symmetric shadow under the nose.
Loop — key ~30–45° off-axis: a small looping nose shadow, the everyday portrait default.
Rembrandt — key further round and slightly lower: a triangle of light on the shadowed cheek.
Split — key at ~90°: exactly half the face lit, half in shadow.

Key light Fill light Rim light

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.