The lighting world today has never been more technologically advanced, with extraordinarily powerful electronics and high output LEDs. With this advancement in technology comes more sophisticated forms of performance measurements, namely in terms of measuring light output. Historically speaking this was most commonly measured in watts, which was effectively the universal language used by industry professionals when gauging a lights output as well as a specific area’s lighting requirements.
In today’s era of modern lighting technology however, simply measuring a light’s performance in watts is not sufficient to quantify its performance. This is especially true considering the global focus on energy efficiency and cost reduction in commercial and industrial facilities. The more accurate the measurement of a lights output, the more precise a lights placement and size can be in order to optimize overall lighting output with minimal electricity usage.
Generally speaking, there are several main types of light output measurements used today. The most commonly used measurement today is lumens, which provides a much more accurate measurement of a light’s true output. Another measurement is candlepower, and more specifically center-beam candlepower (CBCP). Also known as maximum candlepower or center-beam intensity, this measurement focuses specifically on a light’s absolute output in the center of a beam.
CBCP Relevancy in Lighting
CBCP is most relevant in applications using directional lighting, such as overhead lights and flood lights. This is because a light’s lumen output measures the overall output of a light from all angles, which provides less than ideal accuracy for those drafting a photometric lighting plan. One of the biggest issues here is that two different lights may have the identical lumen rating but have significantly different center beam candlepower ratings. This is especially true when lights use different beam angles.
Obviously with directional lighting, measuring using the actual maximum output of the center of the beam is going to be the best way to properly plan out a lighting setup, since the intensity of light hitting the main area is the most important factor as opposed to overall lumen output. It is for this reason that CBCP is highly relevant for applications such as landscape lighting, overhead lighting and general purpose flood lighting.
Certain applications may even require a combination of different CBCP outputs in order to illuminate both broad and specific areas in the same building, nessicating the use of different fixtures or bulbs. For example, a light mounted above a reception room seating area usually will have a lower CBCP in favor of having a broader beam pattern that allows for a more spread out lumen output. In this same room however, lighting mounted above the reception desk will normally have a higher CBCP rating in order to provide the best illumination to staff and clients while completing paperwork.