Luminance Converter
Convert luminance measurements between different units quickly and accurately
Convert Luminance
Popular Luminance Conversions
Quickly convert between the most commonly used luminance units.
Understanding Luminance Measurements
Luminance conversions are essential for various applications, from lighting design and photography to everyday measurements and environmental science. Understanding luminance conversions ensures accurate and consistent results across different measurement systems.
Common Luminance Units
Metric Units
- Candela per Square Meter (cd/m²)
- Nit (nt)
- Stilb (sb)
- Apostilb (asb)
Other Units
- Foot-lambert (fL)
- Lambert (L)
- Millilambert (mL)
- Candela per Square Foot (cd/ft²)
Common Applications
| Field | Measurement Types | Typical Uses |
|---|---|---|
| Lighting Design | Candela per Square Meter, Foot-lambert | Light fixtures, room lighting |
| Photography | Candela per Square Meter, Nit | Camera settings, image brightness |
| Display Technology | Nit, Foot-lambert | Screen brightness, display calibration |
| Environmental Science | Candela per Square Meter, Lambert | Light pollution, natural lighting |
Conversion Tips
- Use a luminance meter for precise luminance measurements
- For quick estimates: 1 foot-lambert = 3.426259 candela per square meter
- Remember that 1 nit = 1 candela per square meter
- For display brightness, use nits or foot-lamberts
- For lighting design, use candela per square meter or foot-lamberts
Luminance Conversions
| Conversion | Formula/Rule | Quick Answer |
|---|---|---|
| Candela per Square Meter to Foot-lambert | 1 fL = 3.426259 cd/m² | Divide cd/m² by 3.426259 |
| Foot-lambert to Candela per Square Meter | 1 cd/m² = 0.291863 fL | Multiply fL by 3.426259 |
| Candela per Square Meter to Nit | 1 nt = 1 cd/m² | 1 cd/m² = 1 nt |
| Nit to Candela per Square Meter | 1 cd/m² = 1 nt | 1 nt = 1 cd/m² |
| Candela per Square Meter to Lambert | 1 L = 3183.099 cd/m² | Divide cd/m² by 3183.099 |
| Lambert to Candela per Square Meter | 1 cd/m² = 0.000314 L | Multiply L by 3183.099 |
| Candela per Square Meter to Apostilb | 1 asb = 0.31831 cd/m² | Divide cd/m² by 0.31831 |
| Apostilb to Candela per Square Meter | 1 cd/m² = 3.14159 asb | Multiply asb by 0.31831 |
Our luminance conversion tool provides accurate conversions between all major luminance units, making it easy to switch between different systems. Whether you're working in lighting design, photography, or environmental science, our converter ensures precise luminance conversions for any application.
Luminance Conversion Questions
Everything you need to know about luminance measurements and conversions
What is luminance and how does it differ from brightness?
Luminance is a photometric measure of the luminous intensity per unit area of light traveling in a given direction. It describes how much luminous intensity will be perceived by an eye looking from a particular direction. Brightness, while related, is a subjective perception that depends on the human visual system and viewing conditions.
What are typical luminance values for everyday objects?
Common luminance values: computer monitors (100-400 cd/m²), television screens (100-1000 cd/m²), white paper in daylight (30 cd/m²), clear sky (8000 cd/m²), sun's surface (1.6 billion cd/m²), full moon (2500 cd/m²), candle flame (10,000 cd/m²). These values help calibrate display devices and lighting systems.
How do I convert between cd/m² and foot-lamberts?
To convert cd/m² to foot-lamberts, multiply by 0.2919. To convert foot-lamberts to cd/m², multiply by 3.426. For example: 100 cd/m² = 100 × 0.2919 = 29.19 foot-lamberts. Foot-lamberts are commonly used in the US cinema and display industries.
What's the difference between luminance and illuminance?
Luminance (cd/m²) measures light emitted or reflected from a surface in a specific direction. Illuminance (lux or foot-candles) measures light falling on a surface from all directions. Luminance is what your eye sees; illuminance is what hits the surface. They're related but measure different aspects of lighting.
Why do display specifications use different luminance units?
Different industries adopted different units: cd/m² (nits) are standard for modern displays and international specifications. Foot-lamberts are traditional in US cinema projection. Stilbs and lamberts are used in scientific applications. The choice often depends on industry tradition and the magnitude of typical values.
How does viewing angle affect luminance measurements?
Luminance is directional - it can vary significantly with viewing angle, especially for LCD displays and reflective surfaces. This is why luminance is defined for a specific direction. OLED displays typically have more consistent luminance across viewing angles compared to LCD displays, which can show significant luminance drops at extreme angles.
What luminance levels are safe for human vision?
Comfortable viewing: 50-200 cd/m² for computer work. Eye strain threshold: around 1000 cd/m². Temporary discomfort: 10,000+ cd/m². Potential eye damage: 100,000+ cd/m² with prolonged exposure. These are general guidelines - individual sensitivity varies, and duration of exposure is critical for safety assessments.
How is luminance used in HDR display technology?
HDR (High Dynamic Range) displays use extended luminance ranges to better represent real-world brightness variations. Standard displays: ~100 cd/m² peak. HDR displays: 400-4000+ cd/m² peak. HDR content is mastered for specific peak luminance values, and displays tone-map content based on their capabilities. This creates more realistic and visually impressive images.
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