1. What is the Watts to Candlepower Formula?

The Watts to Candlepower formula converts electrical power consumption (in watts) to luminous intensity (in candlepower) by accounting for the efficacy of the light source and the solid angle of the light beam.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( cp \) — Candlepower (candela)
• \( W \) — Electrical power in watts
• \( Eff \) — Efficacy in lumens per watt (lm/W)
• \( Solid\ Angle \) — Beam angle in steradians (sr)

Explanation: The formula calculates luminous intensity by considering the total luminous flux (watts × efficacy) distributed over a specific solid angle.

3. Importance of Candlepower Calculation

Details: Candlepower measurement is crucial for lighting design, beam intensity specification, and comparing the performance of different light sources in focused applications.

4. Using the Calculator

Tips: Enter power in watts, efficacy in lumens per watt, and solid angle in steradians. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is candlepower?
A: Candlepower is a unit of measurement for luminous intensity, describing how much light is emitted in a particular direction.

Q2: How is solid angle measured?
A: Solid angle is measured in steradians (sr), which represents the three-dimensional angular span of a light beam.

Q3: What is typical efficacy for different light sources?
A: Incandescent: 10-17 lm/W, LED: 80-120 lm/W, Fluorescent: 50-100 lm/W. Efficacy varies by technology and quality.

Q4: Why is candlepower important in lighting design?
A: It helps determine how focused or dispersed light will be, which is critical for applications like spotlights, flashlights, and automotive headlights.

Q5: How does beam angle affect candlepower?
A: A narrower beam angle (smaller solid angle) results in higher candlepower for the same luminous flux, creating a more focused beam.