Chromaticity Coordinates To Color Temperature Calculator

McCamy's CCT Formula:

\[ CCT = 449n^3 + 3525n^2 - 6823n + 5520.23 \] \[ n = \frac{x - 0.3320}{0.1858 - y} \]

Correlated Color Temperature (CCT):

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1. What Is The McCamy's CCT Formula?

McCamy's formula calculates correlated color temperature (CCT) from CIE chromaticity coordinates (x,y). It provides an accurate estimation of color temperature for light sources based on their position in the chromaticity diagram.

2. How Does The Calculator Work?

The calculator uses McCamy's CCT formula:

\[ CCT = 449n^3 + 3525n^2 - 6823n + 5520.23 \] \[ n = \frac{x - 0.3320}{0.1858 - y} \]

Where:

\( CCT \) — Correlated Color Temperature (Kelvin)
\( n \) — Intermediate variable calculated from x and y coordinates
\( x \) — CIE 1931 chromaticity x-coordinate
\( y \) — CIE 1931 chromaticity y-coordinate

Explanation: The formula approximates the relationship between chromaticity coordinates and color temperature, providing a mathematical correlation between the two parameters.

3. Importance Of Color Temperature Calculation

Details: Correlated color temperature is crucial in lighting design, photography, display calibration, and color science for characterizing the color appearance of light sources and ensuring color consistency across different applications.

4. Using The Calculator

Tips: Enter CIE 1931 chromaticity x and y coordinates (values between 0 and 1). The calculator will compute the correlated color temperature in Kelvin. Note: y cannot be exactly 0.1858 as this would cause division by zero.

5. Frequently Asked Questions (FAQ)

Q1: What Are CIE Chromaticity Coordinates?
A: CIE 1931 chromaticity coordinates (x,y) define a color's position in the CIE color space, representing the color independent of luminance.

Q2: What Is Correlated Color Temperature?
A: CCT describes the color appearance of a light source by comparing it to a theoretical black body radiator, measured in Kelvin (K).

Q3: What Is The Typical Range Of Color Temperatures?
A: Common ranges include: Warm white (2700-3000K), Cool white (3500-4100K), Daylight (5000-6500K). Lower temperatures appear warmer (reddish), higher temperatures appear cooler (bluish).

Q4: What Are The Limitations Of McCamy's Formula?
A: The formula is most accurate for color temperatures between 2000K and 12000K. It may be less accurate outside this range or for light sources with unusual spectral distributions.

Q5: How Are Chromaticity Coordinates Measured?
A: Chromaticity coordinates are typically measured using spectrophotometers or colorimeters that analyze the spectral power distribution of a light source.