Mapping//Calc

THROWLUXARRAYprojection planning utility
v1.0 · 2026

Projector

R = D ÷ WD = W × RW = D ÷ RR — throw ratio · D — distance · W — image width
Solve for:

Light on the wall lux = lumens × projectors ÷ picture area

How the verdict works. Lux needed on the wall, by place (minimum / comfortable / optimal): blackout room 60 / 90 / 120 · darkened room 80 / 120 / 150 · lit room 150 / 200 / 250 · outdoor night, little light 100 / 150 / 200 · outdoor night, city 200 / 250 / 300 · twilight 300 / 500 / 800. Darker walls need more: grey stone ×1.5, brick ×2, dark concrete ×3. Source: Baptiste Jaze, "Lumens vs Lux" — a practitioner guide, not a standard. Real projectors give about 60–70% of their spec lumens (age, eco mode, colours), so keep a margin, and measure the ambient light on site with a lux meter.

Throw classes: ≤ 0.4:1 ultra-short throw (right next to the wall) · 0.4–1.0:1 short throw · 1.0–2.0:1 and above standard / long throw. Take the zoom range from the lens spec sheet, e.g. 1.38–2.28:1.