HED and the LED lights and high-pressure sodium lamp light-emitting efficiency comparison table
Name |
HED |
LED |
High Pressure Sodium Lamp |
|||
Power（W） |
35 |
50 |
36 |
60 |
150 |
250 |
illuminance LX(8M) |
30 |
55 |
14 |
18 |
35 |
50 |
illuminance LX(10M) |
21 |
26 |
12 |
15 |
25 |
35 |
color temperature （K） |
6000 |
6000 |
6000 |
6000 |
2300 |
2300 |
color rendering （Ra） |
75-95 |
75-95 |
70-90 |
70-90 |
30 |
30 |
1) ILLUMINANCE is the total luminous flux incident on a surface, per unit area. It is a measure of the intensity of the incident light.
2) LUMINOUS FLUX or luminous power is the measure of the perceived power of light
2) COLOR TEMPERATURE is a simplified way to characterize the spectral properties of a light source. The color temperature of a light source is determined by comparing its chromaticity with that of an ideal black-body radiator. The temperature (usually measured in kelvin (K)) at which the heated black-body radiator matches the color of the light source is that source's color
temperaturehigher Kelvin temperatures (5000 K or more) are "cool" (green–blue) colors, and lower color temperatures (2700–3000 K) "warm" (yellow–red) colors. Color temperatures in the 2700–3600 K range are recommended for most general indoor and task lighting
| Temperature | Source |
|---|---|
1700 K |
Match flame |
1850 K |
Candle flame |
2800–3300 K |
Incandescent light bulb |
3350 K |
Studio "CP" light |
3400 K |
Studio lamps, photofloods, etc. |
4100 K |
Moonlight, xenon arc lamp |
5000 K |
Horizon daylight |
5500–6000 K |
Typical daylight, electronic flash |
6500 K |
Daylight, overcast |
9300 K |
CRT screen |
| Note: These temperatures are merely approximations; considerable variation may be present. |
|
The CIE 1931 x,y chromaticity space, also showing the chromaticities of black-body light sources of various temperatures (Planckian locus), and lines of constant correlated color temperature.
The COLOR RENDERING INDEX (CRI) is a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source. Color rendering index The color rendering index (RA) is measured on a scale of 1 to 100. Light with just a single colour has a RA of 1 while natural sunlight has a RA of 100.
For colors based on the black body, blue is the "hotter" color, while red is actually the "cooler" color. This is the opposite of the cultural associations that colors have taken on, with "red" as "hot", and "blue" as "cold". The traditional associations come from a variety of sources, such as water and ice appearing blue, while heated metal and fire are of a reddish hue. However, the redness of these heat sources comes precisely from the fact that red is the coolest of the visible colors, the first color emitted as heat increases.