Once upon a time, all things on earth evolved under the care of the sun and the fittest survived. It is the sun that is nourishing human reproduction and survival. Photobiology is now a science.
To human beings, sunlight is the main way of lighting in daily life. In darkness, candle lighting is the main makeup which has lasted for thousands of years. In modern times, filament lighting, incandescent lamp, fluorescent lamp, halogen lamp, and high-pressure gas discharge lamp were typical that offered more lighting convenience. In this century, SSL (= solid state lighting) surpassed and took place of filament lighting. Now LED lighting is getting quick access to varied fields.
Despite the rapid development of lighting technology, the sun is still the best light source.
Challenge of artificial lighting
Let's take a look at the two commonly used light sources, one for road lighting and the other for ordinary lighting.
High pressure sodium lamp
Some people say that the display is to "make up" the goods in the store, so that they can be displayed in front of everyone delicately. Under this, the light is the beauty camera!
High pressure sodium lamp
CCT: 1961 K
CRI Ra: 8, R9:-259
CQS: 34
TLCI: 8
Rf: 27; Rg: 54
Fluorescent lamp
Fluorescent lamp
CCT: 4998 K
CRI Ra: 81, R9: 27
CQS: 80
TLCI: 51
Rf: 78; Rg: 98
It can be seen from the spectral performance of the high pressure sodium lamp and fluorescent lamp above that the blue line is a black body radiation or daylight. Such a light source is far from natural light.
Halogen lamp
Halogen lamp
CCT: 4041 K
CRI Ra: 89, R9: 19
CQS: 88
TLCI: 73
Rf: 89; Rg: 97
Halogen lamp is now a good light source that is frequently used. Still, there is a distinct gap between this lamp and the natural light.
Let's look at the typical spectral line of LED lighting which is now growing fast: one is cold white light, the other is warm white light, and both are high-quality LED light sources.
Warm white LED
Warm white LED
CCT: 3000 K
CRI Ra: 92, R9: 54
CQS: 92
TLCI: 90
Rf: 90; Rg: 97
Cold white LED
LED
CCT: 5600 K
CRI Ra: 93, R9: 71
CQS: 91
TLCI: 95
Rf: 89; Rg: 98
It can be seen that even the LED with CRI up to 92+ has a huge gap with natural light regarding the spectrum, and its expression of color is not perfect. Let alone those with CRI<90. Another bug that LED light source has been criticized is the obvious blue peak.(PS: The blue line in the picture is the black body radiation or daylight.)
At present, there is a way different from blue-light excitation fluorescent powder. The RGB/RGBY LED and OLED are good makeup. They have been improved in color reduction and color gamut.
RGB LED
RGB LED
CCT: 3300 K
CRI Ra: 90
CQS: 90
TLCI:
Rf: 76;
RGBYLED
RGBYLED
CCT: 3300 K
CRI Ra: 90
CQS: 90
TLCI:
Rf: 87
The spectral line is still discontinuous, and the expression of the color is still not good enough.
The ideal light source and spectrum should be as follows: not only meeting the needs of visual lighting, but also meeting the needs of physiological lighting.
Solar spectrum
Solar spectrum
CCT: 5600 K
CRI Ra: 100, R9: 100
CQS: 100
TLCI: 100
Rf: 100; Rg: 100
Black body radiation spectrum
Black body radiation spectrum
CCT: 3200 K
CRI Ra: 100, R9: 100
CQS 100
TLCI: 100
Rf: 100; Rg: 100
Regarding the lighting sources in reality, we certainly do not want the UV and infrared parts to appear.
Healthy lighting
Light has a complex and extensive influence on organisms. In addition to the well-known biological clock, photosynthesis, visual and visual conduction, and psychology, the photosensitizers that absorb light have complex effects on cells, enzymes, effective substance synthesis, biological energy, and even immunity, inheritance, and movement at the macro level, sub-cell and molecular level, and even quantum layer. Still we have superficial cognition or no cognition on many of the effects.
Under such complex light biological interaction, the solar spectrum or the light source close to the solar spectrum is the most suitable light source.
In daily life, indoor working takes a long time, and people cannot reach natural light. The artificial lighting that is lack of certain spectrums of the full spectrum natural light then gradually causes related health problems. It is difficult for artificial lighting to meet the physiological and psychological needs of people.In fact, lighting should meet the needs of visual lighting and physiological lighting at the same time. This is the so-called healthy lighting. On this basis, the product, namely LED-SSLECO Daylight (TM), was launched for the first time. It realizes the natural spectrum based on the UV excited RGB fluorescent powder technology which is completely different.
Return to Nature: ECO Daylight-5600k
It is a comparison about the measured value of close-to-solar-spectrum light source between S Company’s and ECO Daylight’s under the same test conditions.
S Company 5600 K
ECO Daylight 5600 K
t is a comparison about the measured value of close-to-solar-spectrum light source between S Company’s and ECO Daylight’s under the same test conditions.
S Company 5600 K
ECO Daylight5600 K
Return to Nature: ECO Daylight-3200K
It is a comparison about the measured value of close-to-solar-spectrum light source between S Company’s and ECO Daylight’s under the same test conditions.
S Company 3200 K
ECO Daylight 3200 K
It is a comparison about the measured value of close-to-solar-spectrum light source between S Company’s and ECO Daylight’s under the same test conditions.
S Company 3200 K
ECO Daylight 3200 K
Return to nature: Visual expression of ECO Daylight
ECO WW
CCT: 3000 K
Ra: 92, R9: 54
CQS: 92
TLCI: 90
Rf: 90; Rg: 97
It is true but feeble.
ECO Daylight
CCT: 3200 K
Ra: 97, R9: 93
CQS: 92
TLCI: 99
Rf: 98; Rg: 101
True color is restored.
ECO healthy white
CCT: 3200 K
Ra: 98, R9: 97
CQS: 98
TLCI: 99
Rf: 96; Rg: 105
It is true and lively.
Application of ECO Daylight that is a return to nature. It is suitable for scenes that require long hours of manual lighting and focus on health, say schools, offices, hospitals, reading rooms, etc.
Classroom
Reading room
Thanks to the advantages in color performance, it is superior in some work scenes such as museums, showcases and supermarkets that highly require color restoration.
Shop windows
Fresh area in supermarket
In addition, it is promising regarding the applications of high-definition studios and special lighting.
Museum
Drawing
It is foreseeable that the solar spectrum and the black body radiation spectrum will be another new highs of the LED lighting source.