1. What is the TM-30 Fidelity Index?

The TM-30 Fidelity Index (Rf) is a measure of color rendition that evaluates how accurately a light source renders colors compared to a reference illuminant. It is calculated based on the average color difference (ΔE) across 99 color evaluation samples.

2. How Does the Calculator Work?

The calculator uses the TM-30 fidelity index formula:

Where:

• \( Rf \) — Fidelity index (dimensionless)
• \( \Delta E \) — Color difference (dimensionless)

Explanation: The equation calculates the fidelity index by subtracting the average color difference from 100, where a higher Rf value indicates better color fidelity.

3. Importance of Rf Calculation

Details: The TM-30 fidelity index is crucial for evaluating the color quality of light sources in various applications, including lighting design, product development, and quality control in the lighting industry.

4. Using the Calculator

Tips: Enter the average ΔE (color difference) value obtained from 99 color samples. The value must be non-negative.

5. Frequently Asked Questions (FAQ)

Q1: What is a good Rf value?
A: Generally, an Rf value above 80 is considered good, with values above 90 indicating excellent color fidelity.

Q2: How does Rf differ from CRI?
A: Rf provides a more comprehensive evaluation of color fidelity using 99 color samples compared to CRI's 8 samples, resulting in a more accurate representation of color rendering performance.

Q3: What factors affect ΔE values?
A: ΔE values are influenced by the spectral power distribution of the light source, the reflectance properties of the color samples, and the color space used for calculation.

Q4: Can Rf be negative?
A: No, Rf values typically range from 0 to 100, though values below 50 indicate very poor color fidelity.

Q5: How is TM-30 used in lighting standards?
A: TM-30 is increasingly being adopted in lighting standards and specifications to ensure accurate color rendering in various applications, from residential to commercial and museum lighting.