Candle Power

Description

It was not always a case of breaking out the light meter to measure the strength of a candle or wick.

Before modern electric lighting and fancy units like lumens and lux, there had to be an easy way to measure brightness, so there was. The word ‘Candle Power’ was on many lips when speaking of and comparing various sources of light.

What is Candle Power?

Candle power is how many lights from a source in a special direction. Originally, it was referenced to the light given by a standard candle. A one candle power was equal to the brightness of an “average candle” which was a pure spermaceti candle burning at some rated level.

This would mean that a lamp of 10 candlepower gives out as much light as 10 candles burning in the same direction.

The Candle Age or The Early Time of Candles

To establish the intensity and brightness of light sources such as gas lamps or primitive forms of electrical bulbs, people in the 19th century felt the need to devise some kind of measure. This is where the notion of candlepower came into being since candles were only an approximation of reference when no proper measuring instruments had yet been devised.

Scientists, agreed, needed to make the candle which would be a standard; it had to be entirely of pure spermaceti and of specific height and speed of manner of burning. Eventually, it was supplanted by more consistent standards, but the principle remained.

Transition from Candle Power to Candela

“Candle power” is almost obsolete, and candela is the accepted SI measurement of brightness. A candela equals approximately what one candlepower represents under standard conditions.

Candlepower, however, still has informal use especially in older descriptions of products flashlights and searchlights. People by the scores still associate candlepower with just raw brightness in light.

Candle Power vs Lumen vs Lux

This is how the units stack up:

Candle Power is roughly equal to Candela.

Lumen is the total quantity of light in all directions.

Lux is the number of lumens per square meter on a surface.

So, candle power indicates how much light there’s in one direction, lumens how much light there is in total, and lux how much of that hits something.

Measuring Candle Power in the Past

In the past, the most usual method of measuring candle power has been comparison with that of a standard candle under controlled conditions. This involved moving the standard candle (or lamp) nearer to the test candle or lamp successively until it appeared that both are lit with equal and the same degree of brightness, from which mathematical computation was made as to the actual noted brightness.

These methods improved as photometers and other advanced instruments were made. Finally, the standard candle was replaced by more modern instruments, and candlepower became more of a historical term.

Examples in Real Life of Candlepower

Though an old word, people still applied it to their everyday speech. For instance:

One would hear it said that a lamp in a house had so many candlepower, say 50 or 100.

A flashlight rated at 200,000 candlepower would obviously be very bright and quite handy for use in camping or in times of an emergency.

Historically speaking, people used to rate lighthouse illuminations in millions of candle power to judge just how far ships out at sea could see the beam.

Candle Power Still Matters

We use no candles as a standard for measuring light. However, the concept of candle power helps to instantiate how lighting technology has progressed over time and thus how bright something is better. Everyone knows the amount of light given by a candle; therefore, they can easily be apprehended about the strength of a particular “500 candles” flashlight said by someone.

Limits of Candlepower

Now, candle power has been done away with for a few reasons:

It was measuring only that light which traveled in one particular direction.

Its value is not constant for all angles or forms of the light beam.

It assigns itself to an age-old reference, the candle, which modern science and technology no longer identifies with.

Conclusion

Candle Power—an old term but history—tells the user had a big impact on the history of lighting. Before modern lighting units were available, there was an easy way for people to compare brightness. No longer in use, candlepower has some merit while reminding us of the distance traveled by lighting technology from flickering flames to powerful LED beams.

When you light a candle next time, remember that you are holding the very first tool of measuring light.