1. What is Candlepower?

Candlepower (cp) is a unit of measurement for luminous intensity. It describes the amount of light produced in a specific direction. While lumens measure total light output, candlepower measures the intensity of light in a particular direction.

2. How Does the Calculator Work?

The calculator uses the candlepower formula:

Where:

• \( cp \) — Candlepower
• \( lm \) — Total lumens output
• \( \alpha \) — Beam angle in degrees
• \( \pi \) — Mathematical constant pi (approximately 3.14159)

Explanation: This formula converts total light output (lumens) to directional light intensity (candlepower) based on the beam spread angle.

3. Importance of Candlepower Calculation

Details: Candlepower is particularly important in applications where directional lighting is critical, such as spotlights, flashlights, automotive headlights, and theatrical lighting. It helps determine how focused or spread out a light source will be.

4. Using the Calculator

Tips: Enter the total lumens output and the beam angle in degrees. The beam angle should be between 0 and 180 degrees. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between lumens and candlepower?
A: Lumens measure total light output in all directions, while candlepower measures light intensity in a specific direction.

Q2: When should I use candlepower instead of lumens?
A: Use candlepower when you need to know how focused light is in a particular direction, such as for spotlights or directional lighting applications.

Q3: How does beam angle affect candlepower?
A: For the same lumen output, a narrower beam angle results in higher candlepower because the light is more concentrated.

Q4: Is candlepower the same as candela?
A: Candlepower is an older term that is approximately equal to candela. 1 candlepower ≈ 0.981 candela, though they are often used interchangeably in practical applications.

Q5: What are typical candlepower values for common light sources?
A: A typical flashlight might have 10,000-100,000 cp, automotive headlights 20,000-150,000 cp, and searchlights can exceed 1,000,000 cp.