Searchlight Illumination

Drag map markers to set source and target. The tool estimates target illuminance in lux using beam geometry, optical zoom, spill profile, and atmospheric attenuation.

Source settings

1 lux distance (m)

Reference throw distance at spot focus and 100% dimming.

Dimming:

Color temperature:

Beam settings

Beam diameter at lens (cm)

Fixed beam angle

Optical zoom

Fixed beam angle (deg)

Spill settings

Spill intensity ratio:

Spill field angle (deg)

Spill softness:

Atmospheric settings

Enable atmospheric attenuation

Loss at 550 nm (dB/km)

Wavelength exponent

Visualization settings

Visual width exaggeration:

Gradient density: / 100 m

Show spill overlay

Visual saturation (lux)

Cutoff (lux)

Illuminance

Target illuminance

Target distance

Core diameter at target

Spill diameter at target

Center beam intensity

Active beam angle

1 lux range (centerline)

Visual cutoff range

Atmospheric loss at effective wavelength

Target atmospheric transmission

Formula sources

Model uses a flux-conserving optical zoom behavior, two-lobe Gaussian spill profile, and optional atmospheric attenuation.