Luminous Flux Of Light Calculator

Luminous Flux Equation:

\[ \text{Lumens} = \frac{(LRV_{\text{red}} \times 0.2126 + LRV_{\text{green}} \times 0.7152 + LRV_{\text{blue}} \times 0.0722)}{255} \times 100 \]

Luminous Flux:

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1. What is Luminous Flux?

Luminous flux is a measure of the perceived power of light, adjusted for the sensitivity of the human eye to different wavelengths. It's measured in lumens and represents the total amount of visible light emitted by a source.

2. How Does the Calculator Work?

The calculator uses the following equation:

\[ \text{Lumens} = \frac{(LRV_{\text{red}} \times 0.2126 + LRV_{\text{green}} \times 0.7152 + LRV_{\text{blue}} \times 0.0722)}{255} \times 100 \]

Where:

\( LRV_{\text{red}} \) — Light Reflectance Value for red component (0-255)
\( LRV_{\text{green}} \) — Light Reflectance Value for green component (0-255)
\( LRV_{\text{blue}} \) — Light Reflectance Value for blue component (0-255)
0.2126, 0.7152, 0.0722 — Weighting factors for human eye sensitivity

Explanation: The equation accounts for the human eye's different sensitivity to various wavelengths of light, with green being the most perceptible.

3. Importance of Luminous Flux Calculation

Details: Calculating luminous flux is essential for lighting design, determining appropriate light levels for spaces, and comparing the efficiency of different light sources.

4. Using the Calculator

Tips: Enter the LRV (Light Reflectance Value) for each RGB component (values between 0-255). The calculator will compute the luminous flux in lumens.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between luminous flux and illuminance?
A: Luminous flux measures the total visible light emitted (lumens), while illuminance measures how much light falls on a surface (lux or foot-candles).

Q2: Why are the weighting factors different for each color?
A: The human eye is most sensitive to green light (555 nm), less to red, and least to blue, which is reflected in the weighting factors.

Q3: What are typical luminous flux values for light bulbs?
A: A standard 60W incandescent bulb produces about 800 lumens, while a 100W bulb produces about 1600 lumens.

Q4: How does luminous flux relate to energy efficiency?
A: More efficient light sources produce more lumens per watt of electrical power consumed (e.g., LEDs are more efficient than incandescent bulbs).

Q5: Can this calculator be used for colored light sources?
A: Yes, but remember that colored light sources will have their luminous flux weighted according to the human eye's sensitivity to their specific wavelengths.