CBCP (Center Beam Candle Power ) is a measure of the luminous intensity at the center of a directional beam , expressed in candelas (cd) . It is used to indicate the brightness of a beam of light , especially in directional lighting such as spotlights, floodlights, and LED lamps .
1. Features of CBCP
✅ Measure the light intensity at the center of the beam → Not across the entire light spread.
✅ Expressed in candela (cd) → The higher the CBCP value, the brighter the central beam.
✅ Important for directional lighting → Used for spotlights, floodlights and theatre lighting.
✅ Depending on the beam width → A narrower beam (spot) often has a higher CBCP than a wider beam (flood).
✅ More relevant than lumens for targeted lighting → Lumen measures the total light output, while CBCP indicates how intense the light is in the center of the beam.
2. How is CBCP measured?
CBCP is calculated based on the total light output and the beam width :
whereby:
- = total light output of the lamp.
- = beam width in degrees.
📌 Rule of thumb: The smaller the beam , the higher the CBCP at the same number of lumens.
3. Difference between CBCP, Lumen and Lux
| Mate | Meaning | Application |
|---|---|---|
| CBCP (Center Beam Candle Power) | Light intensity at the center of the beam (candela) | Spotlights, floodlights |
| Lumen (lm) | Total light output of a lamp | General lighting, LED lamps |
| Lux (lx) | Light intensity on a specific surface (1 lx = 1 lm/m²) | Workplace lighting, architecture |
📌 Lumen measures how much light a lamp emits, CBCP measures how bright the light beam is at the center, and lux measures how strongly the light illuminates a surface.
4. Applications of CBCP
🔦 Flashlights and spotlights → Determining how powerful the light is in the center.
🎭 Theater & Stage Lighting → Helps direct spotlights onto specific objects.
💡 Architectural lighting → For targeted lighting in museums, galleries and shops.
🚗 Car headlights → Important for the clarity of focused beams.
📺 Projectors → Determines how bright the center of the image is.
💡 In short:
CBCP (Center Beam Candle Power) indicates the intensity of the light in the center of a focused beam . It is expressed in candelas and is especially important for spotlights, floodlights, and other focused light sources .