Convert luminance units — candela/m², nit, stilb, foot-lambert and more.
| Unit | Name | Value |
|---|---|---|
| cd/m² | Candela/Square Meter | 10000 |
| nt | Nit | 10000 |
| L | Lambert | 3.1415915 |
| fL | Foot-lambert | 2918.6343 |
| cd/ft² | Candela/Square Foot | 929.0313 |
| cd/in² | Candela/Square Inch | 6.4516129 |
Formula: Candela/m² = Stilb × 1e+04
Multiply any Stilb value by 1e+04 to get Candela/m².
Reverse: Stilb = Candela/m² × 0.0001
Common luminance values — factor: 1 sb = 1e+04 cd/m²
| Stilb (sb) | Candela/m² (cd/m²) | Context |
|---|---|---|
| 1.000e-06 sb | 0.01 cd/m² | Dark sky |
| 1.000e-05 sb | 0.1 cd/m² | Night scene |
| 0.0001 sb | 1 cd/m² | Very dim |
| 0.001 sb | 10 cd/m² | Dim display |
| 0.005 sb | 50 cd/m² | Monitor |
| 0.01 sb | 100 cd/m² | 100 nit |
| 0.02 sb | 200 cd/m² | 200 nit |
| 0.05 sb | 500 cd/m² | 500 nit |
| 0.1 sb | 1000 cd/m² | HDR10 peak |
| 0.2 sb | 2000 cd/m² | 2000 nit phone |
| 0.5 sb | 5000 cd/m² | 5000 nit |
| 1 sb | 1e+04 cd/m² | 10,000 nit HUD |
| 10 sb | 1e+05 cd/m² | 100,000 nit |
| 100 sb | 1e+06 cd/m² | 1 million nit |
| 1.6e+04 sb | 1.6e+08 cd/m² | Sun surface |
1 sb = 1e+04 cd/m².
nit = cd/m² exactly. Use this as the bridge between SI and legacy units.
Multiply result by 0.0001 to recover the original sb value.
Specifies monitor, TV, and smartphone panel brightness in nits (cd/m²) for HDR grading and product specs.
Calibrates projector output to SMPTE standard of 14 foot-Lamberts for optimal image quality.
Calculates luminance of illuminated surfaces in cd/m² to evaluate glare and visual comfort.
Designs head-up displays exceeding 10,000 nits for daylight readability.
Converts between legacy (Lambert, stilb) and SI (cd/m²) units when reviewing historical data.
Specifies outdoor LED sign brightness in nits for visibility across ambient lighting conditions.
The stilb (sb) is the CGS unit of luminance, equal to 1 candela per square centimeter = 10,000 cd/m². The name comes from the Greek stilbein (to glitter). It was defined in the CGS system in 1918 and predates SI luminance units.
Stilbs are found in older scientific and photometric literature, particularly pre-1970s publications on arc lamps, flashtubes, and laser beam characterization. A carbon arc lamp produces about 15,000 sb (150 million cd/m²).
Interesting fact: The term 'stilb' is rarely used in modern practice outside of historical photometry and some laser physics contexts. The sun's surface luminance of ~2 × 10⁵ sb (2 billion cd/m²) was historically expressed in stilbs in astrophysics literature.
Candela per square meter (cd/m²) is the SI unit of luminance, measuring the intensity of light emitted from a surface per unit area per steradian. It is identical to the nit (nt) in value and replaced the older photometric units in the International System of Units adopted in 1979.
cd/m² is the universal unit in display technology and lighting engineering. Computer monitors: 200–350 cd/m²; smartphone screens: 600–2,000 cd/m²; the sun's surface: about 1.6 × 10⁹ cd/m². SDR content is mastered at 100 cd/m²; HDR10 peaks at 1,000–10,000 cd/m².
Interesting fact: The minimum luminance the human eye can detect is about 10⁻⁶ cd/m² (starlight). The maximum comfortable luminance for sustained viewing is about 1,000 cd/m². The Sun at midday has a luminance of approximately 1.6 billion cd/m².
Luminance measures how bright a surface appears to a human observer. The SI unit is cd/m² (identical to the nit used in display industry). Older units — Lambert, foot-Lambert, and stilb — remain in cinema, photometry, and legacy specs. Key anchors: 100 cd/m² = SDR reference; 1,000 cd/m² = HDR10 peak; 14 fL = 48 cd/m² = SMPTE cinema standard.
Exact factor: 1 sb = 1e+04 cd/m². Reverse: 1 cd/m² = 0.0001 sb.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.