Technical meaning
- Candela describes directional intensity rather than total emitted light.
- It helps explain why the same lumen package can feel concentrated in one beam and broad in another.
Calculation use
- Candela is not normally the main input for the simple room calculators on this site.
- It belongs beside beam, aiming and glare discussions where direction matters.
Not the same as
- Candela is not lumens. Lumens are total visible output; candela is directional intensity.
- Candela is not lux by itself. Illuminance still depends on distance, angle and the assessed surface.
Australian context
- Australian lighting schedules may show intensity data in photometric files, especially for floodlights, optics and glare-sensitive locations.
Examples
| Example | Value | Planning note |
|---|
| Narrow optic | higher directional intensity | Can create a concentrated beam from the same lumen output. |
|---|
| Wide optic | lower directional intensity | Spreads light across a larger footprint. |
|---|
| Glare view | direction matters | Brightness toward the eye can matter as much as total output. |
|---|
Calculation limits and records
- Candela is a directional unit explanation. Detailed intensity and glare work needs photometric information for the actual luminaire and layout.