#Lumens to candela how to

It is important to note that the lumen measures the luminosity perceived by the human eye, which is more sensitive to light at the center of the visible spectrum than at its extremities. Historically, the lumen was defined by its inventor (Perley Nutting at the beginning of the 20th century) as the total luminous flux emitted by a source of wavelength of 555 nanometers with an intensity of 1/683 watt (in 1979, this definition was simplified by introducing the candela, see below our paragraph on the candela). The amount of light emitted by a bulb is measured in lumen. In addition, two bulbs of the same technology can have very different yields, depending in particular on the quality of their construction and of the materials that are used. Each technology (fluo-compact, halogen, traditional incandescent, incandescent halogen, LED) shows a different performance. This transformation is not perfect, a significant proportion of the energy is transformed into heat. The meaning of the technical terms that appear in the descriptions of the modern lights: lumen, lux, candela.Ģ- Luminous power and energy efficiency of the bulbĪ light bulb is like an energy transformer: it consumes electrical power – which goes to your electricity bill – and transforms part of it into light.That lighting fixtures also have of their own efficiency.

#Lumens to candela how to

How to measure the energy efficiency of a light bulb.

It explains the main parameters used to describe the characteristics of the modern lights, and in particular: If you regret the time when it was enough to read the consumption in watt on the box of your bulb to choose the luminous intensity that you needed, then this page is for you. Calculate the parameters for the lighting that you need