What is the Light Converter?
The Light Converter is a comprehensive online tool that allows you to convert between various light and optical measurement units across 5 major categories: Luminance, Luminous Intensity, Illumination, Digital Image Resolution, and Frequency Wavelength. With support for 48+ units, this converter is essential for photographers, lighting designers, optical engineers, and anyone working with light measurements.
Categories and Units
1. Luminance (10 units)
Luminance measures the brightness of a surface or light source as perceived by the human eye. It's commonly used in display technology, cinema projection, and automotive lighting.
- Candela/Square Meter (cd/m²) - SI unit of luminance
- Nit (nit) - Same as cd/m², commonly used for displays
- Footlambert (fL) - Used in cinema projection (1 fL = 3.426 cd/m²)
- Lambert (L) - CGS unit (1 L = 3183.1 cd/m²)
- Stilb (sb) - 1 sb = 10,000 cd/m²
- Candela/Square Centimeter, Apostilb, Blondel
Example: A typical computer monitor has a luminance of 200-300 nits (cd/m²).
2. Luminous Intensity (8 units)
Luminous Intensity measures the amount of light emitted by a source in a particular direction. The SI unit is the candela (cd).
- Candela (cd) - SI base unit for luminous intensity
- Candlepower (cp) - Older unit (1 cp ≈ 0.981 cd)
- Candle - Historical unit based on actual candles
- Decimal Candle, Hefner Candle, International Candle, Pentane Candle
Example: A standard household LED bulb might have a luminous intensity of 100-200 candelas.
3. Illumination (9 units)
Illumination (or illuminance) measures the amount of light falling on a surface. It's crucial for lighting design, photography, and workplace safety standards.
- Lux (lx) - SI unit, 1 lux = 1 lumen/m²
- Footcandle (fc) - Imperial unit (1 fc = 10.764 lux)
- Phot (phot) - CGS unit (1 phot = 10,000 lux)
- Lumen/Square Meter (lm/m²) - Same as lux
- Lumen/Square Centimeter, Lumen/Square Foot, Nox
Common illumination levels:
- Sunlight: ~100,000 lux
- Office lighting: 300-500 lux
- Living room: 50-150 lux
- Full moon: ~0.25 lux
4. Digital Image Resolution (8 units)
Digital Image Resolution measures the detail density of digital images, crucial for printing, scanning, and display quality.
- DPI (Dots Per Inch) - Standard for printers
- PPI (Pixels Per Inch) - Standard for displays (equivalent to DPI)
- Dot/Centimeter - Metric equivalent (1 dot/cm = 2.54 dpi)
- Dot/Meter, Pixel/Centimeter, Pixel/Meter
Common resolutions:
- Standard print: 300 dpi
- High-quality print: 600-1200 dpi
- Screen display: 72-96 ppi
- Retina display: 220-400 ppi
5. Frequency Wavelength (13 units)
Frequency and Wavelength are inversely related properties of electromagnetic radiation. This converter uses the speed of light (c = 299,792,458 m/s) to convert between them using the formula: f = c / λ
Frequency Units (5 units):
- Hertz (Hz) - Cycles per second
- Kilohertz (kHz) - 1,000 Hz
- Megahertz (MHz) - 1,000,000 Hz
- Gigahertz (GHz) - 1,000,000,000 Hz
- Terahertz (THz) - 1,000,000,000,000 Hz
Wavelength Units (8 units):
- Nanometer (nm) - 10⁻⁹ meters (visible light: 400-700 nm)
- Micrometer (μm) - 10⁻⁶ meters (infrared)
- Angstrom (Å) - 10⁻¹⁰ meters (X-rays, UV)
- Millimeter, Centimeter, Meter, Kilometer
Visible Light Spectrum:
| Color | Wavelength (nm) | Frequency (THz) |
|---|---|---|
| Red | 620-750 | 400-484 |
| Orange | 590-620 | 484-508 |
| Yellow | 570-590 | 508-526 |
| Green | 495-570 | 526-606 |
| Blue | 450-495 | 606-668 |
| Violet | 380-450 | 668-789 |
How to Use the Light Converter
- Select Category: Choose from Luminance, Luminous Intensity, Illumination, Digital Image Resolution, or Frequency Wavelength
- Enter Value: Type the numerical value you want to convert
- Select From Unit: Choose the unit you're converting from
- Select To Unit: Choose the unit you're converting to
- Click Convert: Get instant, accurate results with 6 decimal precision
Common Use Cases
Photography & Videography
Convert between lux and footcandles to determine proper lighting for shoots. Calculate illumination levels for different scenes and ensure consistent exposure.
Display Technology
Compare monitor brightness in nits (cd/m²) across different manufacturers. Evaluate HDR display capabilities and cinema projection standards.
Lighting Design
Design workplace lighting to meet safety standards (typically 300-500 lux for offices). Calculate illumination requirements for different spaces.
Print & Graphics
Convert between DPI and PPI for print preparation. Ensure images meet resolution requirements for professional printing (300+ dpi).
Optical Engineering
Convert between wavelength and frequency for laser specifications, fiber optics, and spectroscopy applications. Analyze electromagnetic spectrum properties.
Color Science
Determine wavelengths for specific colors in the visible spectrum. Calculate frequency ranges for optical filters and sensors.
Key Formulas
- Frequency to Wavelength: λ = c / f (where c = 299,792,458 m/s)
- Wavelength to Frequency: f = c / λ
- Lux to Footcandle: fc = lx / 10.764
- Footcandle to Lux: lx = fc × 10.764
- DPI to Dot/cm: dot/cm = dpi / 2.54
Why Use Our Light Converter?
- ✅ 48+ Units - Comprehensive coverage of all light measurement units
- ✅ 5 Categories - Organized by measurement type for easy navigation
- ✅ Bidirectional Conversion - Convert between frequency and wavelength seamlessly
- ✅ High Precision - 6 decimal places for accurate scientific calculations
- ✅ Free & Fast - No registration required, instant results
- ✅ Mobile Friendly - Works on all devices
- ✅ Scientifically Accurate - Uses standard conversion factors and formulas