Candlepower is the SI (Standard International) unit of luminous intensity. Luminous intensity can be defined as the power emitted by light source in a particular direction. Candlepower is an older unit, which is used to represent the luminous intensity emitted particularly by a candle. Later, this definition was generalized to represent all types of light, instead of particular candle light. The new unit for measuring luminous intensity of every type of light is now candela. Candela is a Latin word for “candle”. This modern unit defines luminous intensity more precisely. The new unit candela for the measurement of light intensity was introduced in 1948. Before both the units, Candela and Candlepower, the unit “Candle” was used to measure the intensity of light.

A candle normally produces 13 lumens of visible light with 40 watts of heat. These reading may vary, if observed from different types of candles, because these observations depend upon the characteristics of wick of the candle. But most commonly, these readings are attained with a standard wax wick candle. You can compare this with a tube light. A 40 watt incandescent light bulb produces nearly 500 lumens of visible light, with the same amount of power. Candles were considered to be a very cheap and a very good way and source, in order to get light. Candles have been traditionally used over the years, in order to get heat and light. You can also say that candles are a natural, more reliable and cheaper way to produce light and the output of light from the candles was not as low as the people of old times, thought. Candles were the main output of light in the past, when there was no electricity. These days, there are so many candles that are made from some special ingredients and materials in order to provide more output of light than before.