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Light Intensity Formula:
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Light intensity, also known as illuminance or irradiance, measures the power of light per unit area. It quantifies how much light energy falls on a surface and is crucial in various fields including photography, lighting design, and solar energy applications.
The calculator uses the fundamental light intensity formula:
Where:
Explanation: This formula calculates the power density, showing how concentrated the light energy is over a given surface area.
Details: Accurate light intensity calculation is essential for designing efficient lighting systems, optimizing solar panel placement, ensuring proper illumination for photography and videography, and maintaining healthy plant growth in agriculture.
Tips: Enter power in watts (W) and area in square meters (m²). Both values must be positive numbers. The calculator will compute the light intensity in watts per square meter (W/m²).
Q1: What is the difference between illuminance and irradiance?
A: Illuminance measures visible light intensity in lux, while irradiance measures total electromagnetic power in W/m², including non-visible wavelengths.
Q2: What are typical light intensity values?
A: Direct sunlight is about 1000 W/m², office lighting is 300-500 lux, while moonlight is only 0.1-0.3 lux.
Q3: How does distance affect light intensity?
A: Light intensity decreases with the square of the distance from the source according to the inverse square law.
Q4: Can this calculator be used for LED lighting?
A: Yes, but note that LED efficiency varies, and the actual luminous output may differ from the electrical power input.
Q5: How do I convert between lux and W/m²?
A: Conversion depends on the light spectrum. For sunlight, approximately 120 lux = 1 W/m², but this varies with light source type.