Inverse Square Light Drop-Off
Lux falloff, f-stop loss & intensity ratio as distance changes.
Lux is measured at Dist 1 and projected to Dist 2.
Intensity at Dist 2
250 Lux
Relative light remaining
25% of D1100% at D1
Doubling distance = 4× less light (−2 stops). Move lights closer, don't just crank power.
Did you know?
The inverse square law is why the Sun's surface is blindingly bright but delivers gentle warmth at 150 million km — distance is a silent light killer.
Formula
Intensity₂ = Intensity₁ × (Dist₁ / Dist₂)²
FAQs
Why the 4× drop?
Light spreads over a 2D surface area, so doubling distance quadruples the area the light must cover.