Solar Spectrum

The solar spectrum at Earth's surface peaks in the visible band around 500 nm but extends from UV (under 380 nm) through visible (380–780 nm) to near-infrared (780–2500 nm) and beyond.

Window film performance specifications are measured against this spectrum, with key bands isolated for UV rejection, visible light transmission and IR rejection.

For Singapore conditions, where solar irradiance can exceed 1000 W/m² at noon, all three bands contribute to cabin heating. A quality film addresses each band, with IR being the largest contributor to felt heat.