1. What is Correlated Color Temperature?

Correlated Color Temperature (CCT) describes the color appearance of light emitted by a source, measured in Kelvin (K). It indicates whether light appears warm (yellowish) or cool (bluish) relative to a black body radiator.

2. How Does the Calculator Work?

The calculator uses the peak wavelength formula:

Where:

• \( CCT \) — Correlated Color Temperature (Kelvin)
• \( \lambda_{max} \) — Peak wavelength (nanometers)
• \( 2.897 \times 10^6 \) — Wien's displacement constant

Explanation: This formula is derived from Wien's displacement law, which relates the peak wavelength of black body radiation to its temperature.

3. Importance of CCT Calculation

Details: CCT is crucial in lighting design, photography, display technology, and color science for ensuring accurate color reproduction and appropriate lighting environments.

4. Using the Calculator

Tips: Enter the peak wavelength in nanometers (nm). The value must be greater than zero. Typical visible light wavelengths range from 380 nm to 780 nm.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between wavelength and color temperature?
A: Shorter wavelengths (blue/violet) correspond to higher color temperatures, while longer wavelengths (red/orange) correspond to lower color temperatures.

Q2: What are typical CCT values for common light sources?
A: Candlelight: 1500-2000K, Incandescent: 2700-3000K, Daylight: 5000-6500K, Overcast sky: 6500-10000K.

Q3: How accurate is this calculation for real light sources?
A: This provides an approximation based on black body radiation. Real light sources may have different spectral distributions.

Q4: What is Wien's displacement constant?
A: It's approximately 2.897771955×10⁻³ m·K, representing the constant in Wien's displacement law \( \lambda_{max} T = b \).

Q5: Can this formula be used for all light sources?
A: It works best for thermal radiators (incandescent, sunlight). For LEDs and fluorescent lights, more complex calculations may be needed.