Knowledge of the lighting

1. 1)    Kelvin color temperature

Kelvin color temperature refers that the people's eyes can feel the change under the different energies of the light wave, it is used as a scale of the light color of light source. the unit is K.

Here’s commen natural lighting source in our daily life

 

1. 2)    Luminous flux

The people’s eyes can feel the sum of the radiant energy glow from a light source. The unit is lumen or lm. Also can be called beam (Φ)

 

1. 3)    Luminous Efficiency

Luminous Efficiency refers to how much luminous flux can be output per 1 watt of the light source. Expressed by the ratio of luminous flux to power consumption, the unit is lm/W.

Early incandescent lamps and fluorescent lamps can roughly use wattage to judge the brightness. Higher wattage means need more electricity, and the brightness will be higher accordingly. These years, with the development of LED field. If the same brightness, the incandescent lamps may consume 85W of the power. The led only consume 12W. So, nowadays, we can’t judge the brightness by the wattage. When we need the high brightness items, we need to check the luminous efficiency of the items, high light efficiency means the higher brightness.

 

1. 4)    Color rendering

Color rendering refers the light source presents the color degree of the real object, unit: RA. Higher color rendering means the color of the object appears more natural. Value: 0-100. Generally, the color rendering index is above CRI80, that is good light source.

1. 5)    Luminous intensity

Luminous intensity (Unit: Candela/CD), it refers how bright the light source is.

MCD is a unit of LED brightness.

In LED field, How to change the MCD into lumen?

Change MCD into lumen, normally we divide MCD by 333. Such as SMD5050 RGB series, Green: 1500MCD/LED.  that is 4.5lumen/LED. This is parameters is almost same as the EVERFINE.

 

1. 6)    Luminance

Kindly note it refers the brightness of the lighting emitting surface instead of the light source, which means the luminous flux emitted perpendicular by the luminous surface to the specific direction or reflected. That is the real brightness that people’s eyes feel. (Unit: 1nt = cd/㎡).

 

Noted：different place has different reflection coefficient, or absorption coefficient. For example, when we put 1 white paper and 1 black paper in a place with same illuminance, the brightness difference we feel with the naked eye is very big. The reflection coefficient of white paper is about 80%, while the reflection coefficient of black paper is only 3%. (The parameters are for reference only, the actual is based on the final inspection)

 

1. 7)    Illuminance

It refers the total lumen from the place that is illuminated by the light source.(Unit: Lx/Lux).

Illuminance can be measured directly via Illuminometer. When the object is uniformly illuminated by light, we can be obtained on 1 lumen from an area of the 1 square meter.

The illuminance is 1Lux.