Good afternoon dear friends! Once again, welcome everyone to the “Electrician in the House” website. Recently, the demand for LED products has been constantly increasing. The use of innovative light sources is used in various sectors of the national economy.
New cars are equipped with LED lamps, houses, business premises and outdoor advertising stands are illuminated. They are used in spotlights, street and office lamps, as well as in many other human inventions.
Concept does not even imply the amount of heat they give off, but has a completely different meaning. This is the visual effect of the perception of a light source by the human eye. As the color spectrum of light approaches the sun (yellow), the “warmth” of each lamp is determined.
You can also make an association with a candle flame, and you will immediately understand how this phenomenon is described. On the contrary, a bluish tint of light is associated with a cloudy sky and snowy night glow. This light evokes cold, pale images in us. But there is a definite scientific explanation for everything.
When a piece of metal is heated, it develops a characteristic glow. First the color range is in red tones. As temperatures rise, the color spectrum gradually begins to shift toward yellow, white, bright blue and violet.
Each color of metal glow has its own temperature range, which makes it possible to describe the phenomenon using known physical quantities. This helps to characterize color temperature not as a randomly taken value, but as a certain heating period until the required spectrum color is obtained.
The color spectrum of LED crystals is somewhat different. It is different from the possible colors of metal glow due to a different method of its origin. But the general idea remains the same: to obtain the selected shade you will need a certain color temperature. It is worth noting that this indicator is in no way related to the amount of heat generated by the lighting fixture.
Once again I want to note that there is no need to confuse color temperature and the physical temperature (amount of heat) that your lamp emits, these are different indicators.
LED color temperature scale
Today's domestic market offers a huge range of light sources based on LED crystals. They all operate in different temperature ranges. Usually they are chosen depending on the location of the intended installation, because each such lamp creates its own, individual look. The same room can be significantly transformed by changing only the color of the lighting.
To optimally use each LED light source, you should decide in advance which color is most convenient for you. The concept of color temperature is not specifically related to LED lamps, it cannot be tied to a specific source, it depends only on the spectral composition of the selected radiation. Each lighting device has always had a color temperature, it’s just that when standard incandescent lamps were released, their glow was only “warm” yellow (the emission spectrum was standard).
With the advent of fluorescent and halogen lighting sources, white “cold” light came into use. LED lamps are characterized by an even wider range of colors, due to which the independent choice of optimal lighting has become more complicated, and all its shades began to be determined by the material from which the semiconductor was made.
Relationship between color temperature and lighting
A clear knowledge of the tabular values of this characteristic helps to understand what color will be discussed further. Each of us has a different color perception, so only a few can visually determine the coldness or warmth of the light flux.
The average indicators of a group of products operating in a given spectrum are taken as a basis, and when making the final selection of LED lamps, the specific conditions of their operation (installation location, illuminated space, purpose, etc.) are taken into account.
Today, all lighting sources, depending on their luminescence range, are classified into three main groups:
- - warm white light– operate in the temperature range from 2700K to 3200K. The spectrum of warm white light they emit is very similar to the glow of a conventional incandescent lamp. Lamps with this color temperature recommended for use in residential premises.
- - day white light(normal white) – in the range from 3500K to 5000K. Their glow is visually associated with morning sunlight. This is a neutral range luminous flux that can be used in apartment technical rooms (hallway, bathroom, toilet), offices, classrooms, production workshops, and so on.
- - cold white light(day white) – in the range from 5000K to 7000K. Reminds me of bright daylight. They illuminate hospital buildings, technical laboratories, parks, alleys, parking lots, billboards, etc.
| Color temperature | Light type | Where is it used? |
| 2700 K | light “warm white”, “reddish white”, warm part of the spectrum | This is typical for conventional incandescent lamps, but can also be found in LED lamps. Used in a cozy home interior, promotes rest and relaxation. |
| 3000 K | light “warm white”, “yellow-white”, warm part of the spectrum | It occurs in some halogen lamps, and is also found in LED lamps. A little colder than the previous one, but also recommended for residential use. |
| 3500 K | “day white” light, the white part of the spectrum | It is created by fluorescent tubes and some modifications of LED lamps. Suitable for apartments, offices, public spaces. |
| 4000 K | “cool white” light, the cold part of the spectrum | An indispensable attribute of the high-tech style, but it is overwhelming with its deathly pallor. Used in hospitals and underground facilities. |
| 5000 K - 6000 K | “daylight” light “white-blue”, daytime part of the spectrum | An excellent imitation of the day for work and production premises, greenhouses, greenhouses, terrariums, etc. |
| 6500 K | “cold daylight” light “white-lilac”, cold part of the spectrum | Suitable for street lighting, warehouses, industrial lighting. |
From the given characteristics it is clearly seen that when low color temperature red predominates and blue is absent. When the temperature increases, green and blue colors appear, and red disappears.
Where can I find out about this option?
On the packaging of each lighting lamp, manufacturers indicate its technical characteristics. Among all other characteristics, such as power, voltage, network frequency, it is necessary to indicate (this applies not only to LED lamps). You should definitely pay attention to this main factor before purchasing a lamp.
By the way, this characteristic is displayed not only on the packaging, but also on the lamp itself. Here is one example, a 7 W LED lamp with a temperature of 4000K. It is installed in my home, in the kitchen, and shines with pleasant daylight.
And here is another example of the designation on an LED spotlight for plasterboard ceilings, temperature 2800 Kelvin. Lamps with this color temperature shine with a warm light similar to an incandescent lamp and were installed in the bedroom of one of the objects.
Which lamps to choose for the office
The regulatory document SP 52.13330.2011 “Natural and artificial lighting” recommends the use of various radiation sources depending on their type, power, design and characteristics of the luminous flux. Residential premises are required to be equipped with small and low-temperature “warm” lighting devices, and in non-residential buildings larger lamps of normal “white” light must be installed.
It has been proven that white lighting is optimal for the work process, since the part of the blue spectrum it contains has a beneficial effect on a person, helps him concentrate, speeds up the reaction and work processes of the body. It is good to choose radiation sources from 3500K to 5600K, with white or neutral light, with a slightly bluish tint. Such lighting will make it possible to increase performance to the maximum level.
Both fluorescent and LED lamps are suitable, although the latter will provide significant savings in energy resources.
On the contrary, it would be a big mistake to install cool white light fixtures with a range close to 6500K in such a place. This will lead to rapid fatigue of workers, complaints of headaches and a sharp decrease in performance.
Which lamps are suitable for home
In apartments and private houses, white light is not recommended. It is not necessary to place the same lamps everywhere; it is better to use individual recommendations for lighting equipment in such rooms. You can install white neutral lamps in the kitchen, bathroom and hallway. Their temperature can vary from 4000K to 5000K.
But for the bedroom, nursery and rooms where you relax, it is preferable to use warm tones of the light spectrum. The best solution here would be warm white light closer to 2700K to 3200. It will relieve daytime tension, create comfort and allow you to relax.
It is convenient and effective to use normal white light in the reading area and work corner, as well as to illuminate mirrors in front of which makeup is applied. This way you will achieve maximum color contrast and convenience for the actions performed.
Introduction………………………………………………………………………………… 1. The concept of color temperature…………………………………………………………… ….. 1.1. Table of numerical values of color temperature of common light sources………………………………………………………………………………….. 1.2. XYZ chromaticity diagram………………………………………………….
1.3.Sunlight and Color Rendering Index (CRI - color rendering index)..
2. Methods for measuring color temperature……………………………...... Sources of information……………………………………………………….
Introduction.
According to our psychological sensations, colors are warm and hot, cold and very cold. In fact, all colors are hot, very hot, because each color has its own temperature and it is very high. Any object in the world around us has a temperature above absolute zero, which means it emits thermal radiation. Even ice, which has a negative temperature, is a source of thermal radiation. It's hard to believe, but it's true. In nature, the temperature of -89°C is not the lowest; even lower temperatures can be achieved, however, for now, in laboratory conditions. The lowest temperature that is currently theoretically possible within our universe is the temperature of absolute zero and it is equal to -273.15 ° C. At this temperature, the movement of the molecules of the substance stops and the body completely stops emitting any radiation (thermal, ultraviolet, and even more so visible). Complete darkness, no life, no warmth. Some of you may know that color temperature is measured in Kelvin. Anyone who bought energy-saving light bulbs for their home saw the inscription on the packaging: 2700K or 3500K or 4500K. This is precisely the color temperature of the light emitted by the light bulb. But why is it measured in Kelvin, and what does Kelvin mean? This unit of measurement was proposed in 1848. William Thomson (aka Lord Kelvin) and officially approved in the International System of Units. In physics and sciences directly related to physics, thermodynamic temperature is measured in Kelvin. The beginning of the temperature scale report begins at the 0 Kelvin point, which means - 273.15 degrees Celsius. That is, 0K is absolute zero temperature. You can easily convert temperature from Celsius to Kelvin. To do this, you just need to add the number 273. For example, 0°C is 273K, then 1°C is 274K, by analogy, a human body temperature of 36.6°C is 36.6 + 273.15 = 309.75K. That's how it all works out just like that.
Chapter 1. The concept of color temperature.
Let's try to figure out what color temperature is.
Light sources are bodies heated to high temperatures, the thermal vibrations of whose atoms cause radiation in the form of electromagnetic waves of various lengths. Radiation, depending on the wavelength, has its own color. At low temperatures and, accordingly, at longer waves, radiation with a warm, reddish color of the light flux predominates, and at higher temperatures, with a decrease in wavelength, with a cold, blue-blue color. The unit of wavelength is nanometer (nm), 1nm=1/1,000,000mm. Back in the 17th century, Isaac Newton, using a prism, decomposed the so-called white daylight and obtained a spectrum consisting of seven colors: red, orange, yellow, green, blue, indigo, violet, and as a result of various experiments he proved that any spectral color can be obtained by mixing light fluxes consisting of different ratios of three colors - red, green and blue, which were called the main ones. This is how the three-component theory appeared.
The human eye perceives the color of light thanks to receptors, the so-called cones, which have three varieties, each of which perceives one of the three primary colors - red, green or blue and has its own sensitivity to each of them. The human eye perceives electromagnetic waves in the range from 780 to 380 nanometers. This is the visible part of the spectrum. Consequently, the light receivers of information carriers - cinema and photographic film or the camera matrix must have a sensitivity to color identical to the eye. Sensitized films and matrices of video cameras perceive electromagnetic waves in a slightly wider range, capturing infrared radiation (IR) close to the red zone in the range of 780-900 nm and ultraviolet (UV) radiation close to the violet in the range of 380-300 nanometers. This region of the spectrum, in which geometric optics and photosensitive materials operate, is called the optical range.
In addition to light and dark adaptation, the human eye has so-called color adaptation, thanks to which it correctly perceives colors under different sources, with different ratios of wavelengths of primary colors. The film and matrix do not have such properties; they are balanced to a certain color temperature.
The heated body, depending on the heating temperature, has a different ratio of different wavelengths in its radiation and, accordingly, different colors of the light flux. The standard by which the color of radiation is determined is an absolute black body (ABB), the so-called. Planck emitter. An absolutely black body is a virtual body that absorbs 100% of the light radiation incident on it and is described by the laws of thermal radiation. And color temperature is the temperature of the black body in degrees Kelvin, at which the color of its radiation coincides with the color of the given radiation source. The difference between the temperature scale in degrees Celsius, where the freezing point of water is taken as zero, and the scale in Kelvin degrees is -273.16, because the starting point in the Kelvin scale is the temperature at which any movement of atoms in the body stops and, accordingly, any radiation stops , the so-called absolute zero, corresponding to a Celsius temperature of -273.16 degrees. That is, 0 degrees Kelvin corresponds to a temperature of -273.16 degrees. Celsius.
The main natural source of light for us is the Sun and various light sources - fire in the form of a fire, matches, torches and lighting devices, ranging from household appliances, technical devices to professional lighting devices created specifically for cinema and television. Both household and professional appliances use various lamps (we will not touch on their operating principles and design differences) with different energy ratios in their emission spectra of primary colors, which can be expressed by color temperature. All light sources are divided into two main groups. The first, with a color temperature (Tc.) 5600 0K, of white daylight (DS), the radiation of which is dominated by the short-wave, cold part of the optical spectrum, the second - incandescent lamps (LN) with Tc. - 32000K and the predominance of the long-wave, warm part in the radiation optical spectrum.
Where does it all begin? Everything starts from scratch, including light radiation. Black color is the absence of light at all. From the point of view of color, black is 0 radiation intensity, 0 saturation, 0 hue (it simply does not exist), it is the complete absence of all colors at all. Why we see an object black is because it almost completely absorbs all the light falling on it. There is such a thing as a completely black body. An absolute black body is an idealized object that absorbs all radiation incident on it and does not reflect anything. Of course, in reality this is unattainable and absolutely black bodies do not exist in nature. Even those objects that seem black to us are not actually completely black. But it is possible to make a model of an almost completely black body. The model is a cube with a hollow structure inside; a small hole is made in the cube through which light rays penetrate into the cube. The design is somewhat similar to a birdhouse. Look at picture (1).
Figure (1). – Model of a completely black body.
Light entering through the hole will be completely absorbed after repeated reflections, and the outside of the hole will appear completely black. Even if we paint the cube black, the hole will be blacker than the black cube. This hole will be a completely black body. In the literal sense of the word, the hole is not a body, but only clearly demonstrates to us an absolutely black body.
All objects exhibit thermal radiation (as long as their temperature is above absolute zero, that is -273.15 degrees Celsius), but no object is a perfect thermal emitter. Some objects emit heat better, others worse, and all this depending on different environmental conditions. Therefore, a black body model is used. A completely black body is an ideal thermal emitter. We can even see the color of a blackbody if we heat it up, and the color we see will depend on the temperature to which we heat the blackbody. We have come close to the concept of color temperature.
Look at picture (2).
Figure (2). – The color of a completely black body depending on the heating temperature.
a) There is an absolutely black body, we don’t see it at all. Temperature 0 Kelvin (-273.15 degrees Celsius) is absolute zero, the complete absence of any radiation.
b) Turn on the “super-powerful flame” and begin to heat up our absolutely black body. The body temperature, through heating, increased to 273K.
c) A little more time has passed and we already see a faint red glow of a completely black body. The temperature increased to 800K (527°C).
d) The temperature rose to 1300K (1027°C), the body acquired a bright red color. You can see the same color glow when heating some metals.
e) The body has heated up to 2000K (1727°C), which corresponds to an orange glow. Hot coals in a fire, some metals when heated, and a candle flame have the same color.
f) The temperature is already 2500K (2227°C). The glow at this temperature becomes yellow. Touching such a body with your hands is extremely dangerous!
g) White color – 5500K (5227°C), the same color of the glow of the Sun at noon.
h) Blue color of the glow – 9000K (8727°C). In reality, it will be impossible to obtain such a temperature by heating with a flame. But such a temperature threshold is quite achievable in thermonuclear reactors, atomic explosions, and the temperature of stars in the universe can reach tens and hundreds of thousands of Kelvin. We can only see the same blue tint of light, for example, from LED lights, celestial bodies or other light sources. The color of the sky in clear weather is approximately the same color. To summarize all of the above, we can give a clear definition of color temperature. Color temperature is the temperature of a completely black body at which it emits radiation of the same color tone as the radiation in question. Simply put, 5000K is the color that a black body acquires when heated to 5000K. The color temperature of orange is 2000K, which means that a completely black body must be heated to a temperature of 2000K for it to acquire an orange glow.
But the color of the glow of a hot body does not always correspond to its temperature. If the flame of a gas stove in the kitchen is blue-blue, this does not mean that the flame temperature is above 9000K (8727°C). Molten iron in its liquid state has an orange-yellow hue, which actually corresponds to its temperature, which is approximately 2000K (1727°C).
LED products today are a huge success among consumers. In just a couple of years, new light sources began to be used almost everywhere. LED lamps are needed for cars, outdoor advertising, home and other areas of human activity.
But today we will not talk about how these light bulbs are used at home, in public spaces, in cars, etc. In this article we will talk about what the color temperature of LED lamps is and how this indicator affects their heating. But to understand such a concept as LED heating, you need to start with the basics.
The essence of light
Light, as a physical phenomenon, can have various manifestations. In different light, we will see objects and the reality around us in different shades, which will undoubtedly affect our worldview. At the same time, we can perceive objects more clearly or distortedly.
Color temperature and color rendering index are responsible for the correct lighting and how we perceive the surrounding space.
Pay attention! For the optimal selection of any light source (not only LED) for home, street, car and other areas of human activity, it is imperative to take these two parameters into account. Otherwise, you will feel uncomfortable being in a lit room.
LED lamp glow
The color temperature of LED lamps must meet certain requirements so as not to cause inconvenience. This is the main characteristic of any type of light bulb, especially those that are capable of heating. It is worth noting that LED light sources are capable of very minimal heating. Therefore, even though they can get a little warm, they are actively used in tandem with stretch ceilings.
Color temperature determines the spectral composition of light radiation, which must be objectively perceived by human visual analyzers (eyes). This indicator is measured for LED lamps, as with other light sources, using a colorimeter. And it is measured in inverse microdegrees or mireds.
When choosing LED models, the consumer must be familiar with this indicator in order to make the right purchase. There is a corresponding table to determine the optimal color temperature range.
Color temperature table
Pay attention! This indicator is identical to other light bulbs widely used in the world.
When choosing a light source for your home, street or car, you must remember that the light emitted by the light bulb should be as close as possible to the natural level of illumination.
Features of diode light
A light-emitting diode is a semiconductor device that produces a glow when electric current passes through it. The light that such a diode is capable of emitting is located in a fairly narrow spectral range. In this case, the color itself will depend on the material from which the LED semiconductor is made.
The formation of white color in such products is achieved in the following ways:
- combining diodes of different glow colors to produce white light. This method allows you to obtain excellent color quality with the ability to adjust it. But this method is quite expensive, which affects the price of products that are not available to everyone;
- the use of phosphors to coat diodes. This is a fairly cheap and beneficial method that allows you to achieve a higher color rendering coefficient. But here, due to the applied phosphor coating, the luminous efficiency decreases.
Lamp structure
An LED light bulb consists of several diodes or, as they are sometimes called, chips. In addition, there is a driver, which is a device that converts alternating current with a voltage of 220 volts into the direct current necessary to power the diodes. Thanks to this structure, these light sources create a directional luminous flux, which is characterized by the directional angle for the generated glow.
What you need to know
When choosing LED light bulbs, you need to know that they have such a parameter as operating color temperature. It reflects the level at which the light source will produce enough glow. Here it is necessary to remember that car headlights or home lamps must have different glow temperature parameters. Otherwise, they will not be able to effectively illuminate the space around them.
When the temperature is within 5000K, the spectral composition of the emitted light will be more balanced. Here it will be almost identical to daytime sunlight. The color rendering index with these parameters will be equal to 100. However, the maximum color temperature is rarely used, since borderline conditions can harm the eyes.
Color temperature
Pay attention! As the color temperature decreases, the glow will become more red and less blue. And the higher the indicator, the more blue and green colors will be in the glow. This is clearly seen in the example of an incandescent lamp, which creates a glow with a reddish tint.
LED lamps in this aspect have the following positive aspects:
- The lamp housings do not get hot. In fact, heating still occurs here, but it is almost imperceptible. Heating when using this kind of lamps is noticeable only in the example of LED strip. But here, too, the main heating comes only from the power supply. The product bodies themselves do not heat up;
- create high-quality white light, which is most suitable for our eyes when it comes to artificial lighting.
Car lighting
Such parameters have made it possible to widely use LEDs for illuminating homes, streets and cars. It’s worth dwelling on the latter case in more detail, since the car can have LED tuning of both the headlights and the entire body.
However, there are also disadvantages here. So, despite the fact that such products hardly heat up, and their bodies do not deform due to constant overheating, they do not always effectively reproduce other shades of light.
Difference between LED lamps
LED products differ from each other in their color temperature coefficient. Today, all products, regardless of their purpose (street, home, car) are divided into three main groups according to their luminescence range:
- range within 2700-3500K. Such products emit white warm light, which is very similar to the glow of incandescent lamps. Used for residential premises;
- range within 3500-5000K. This is the so-called neutral range. The glow here is called “normal white”. The light emanating from paws working in this range resembles sunlight in the morning. Suitable for technical areas of the house (bathroom, toilet), offices, educational premises;
- range within 5000-7000K. The glow emitted in this range is called “cool or day white” light. It corresponds to bright daylight. It is used for street lighting of parks, alleys, parking lots, billboards, etc.
Different glow of lamps
If the color temperature does not match 5000K, shades, with the exception of white, will have warm tones (if this value is exceeded) or cool tones (if this value is decreased). At the same time, the housings of the light sources do not heat up, which does not in any way affect the service life of these energy-saving light bulbs.
Remember, when choosing such lighting products, you must always give preference to the most suitable color rendering index.
Conclusion
Of course, it is difficult for artificial lighting to compare with natural light, but LED bulbs from all the different models come as close as possible to this. Plus they barely get hot! When deciding to use LED light sources for illumination, you need to be familiar with such an indicator as color temperature. The luminous flux that will have a direct effect on the human visual analyzer depends on this parameter. If you do not take color temperature into account, then your idea will not provide the desired convenience, but will only bring discomfort.
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One of the parameters that can characterize the color shade and its quality is the color temperature of LED lamps. This parameter partially characterizes the brightness level of the lighting device. When you need to look at the color temperature. After all, if the LED light is chosen incorrectly, this will lead to a lack of comfort in the room. Next, we will explain to the readers of the site how to choose this indicator correctly.
Color Temperature Range
Color temperature previously did not have a significant meaning, since an incandescent lamp was used, for which this parameter was standard. As soon as the diode lamp or strip of LEDs appeared, the color gamut expanded and choosing the right LED light became more difficult, since its shade is determined by the semiconductor material. The table below indicates the range of the characteristic under consideration (in Kelvin):
There are three ranges:
- warm white lighting (2700 – 3200);
- natural, daytime (3500 – 6000);
- cold (from 6000).
How to choose the right glow for the street or for the home? For an office, the most acceptable lamp is considered to have a color temperature in the range from 2800 to 6600 K. For example, an incandescent lamp belongs to the first group. This gives comfort and coziness. Natural daylight will be optimal for work.
Optimal indicator
Office
For work, it is recommended to use LED light, which is in the range from 4400 to 5600 K. This means that the light bulb must be white or neutral in color. Due to this, the performance of employees will be maximum. Below is a table that helps you choose the optimal value:
What does the color change affect? If the color temperature is different (yellow, blue or orange), then the performance and, as a result, productivity of employees will decrease. If the LED light has an orange tint, performance is reduced by up to 80%.
Important! Why is a neutral or white light lamp more optimal for work? Because it contains the blue spectrum, which helps speed up reaction and concentration during daytime work.
For office premises and for production, such LED light will be the most optimal, since it increases productivity and efficiency.
Living space
But what is the best way to choose the color temperature of LED lamps for a home or apartment? For example, a light bulb that has a blue spectrum is not used in sleeping rooms (children's or bedroom). In a residential building or apartment, the color temperature is selected individually for each room.
So the lighting temperature for the living room or bedroom is selected so that the LED lamp illuminates in the warm white range (2700 - 3200 K). A glow of this level gives the room coziness and comfort.
In the bathroom, a fluorescent and white lamp (4000 - 5000 K) is used. This light bulb is also suitable for the kitchen. This emission spectrum is suitable for a home office or reading area, and can also be used as plant shelving.
What else is important to know?
The intensity of light depends on several values, but there is no direct relationship between the spectrum and the degree of brightness. But this value, although not considered key, nevertheless establishes the very effectiveness of the glow. For example, a lamp that has the same power, but a different radiation spectrum provides different glow intensities.
The explanation for all this is very simple: a light bulb whose LED light is located in the high value range from 6000 K (cold shades) makes it possible to obtain the brightest lighting. But this works if parameters such as power level and diode type are equivalent.
Do not forget about the natural process of reducing the intensity of the glow (clouding of crystals). This is the so-called degradation, when after a certain time the lighting fixtures become weaker and less efficient. In order for the light source to work longer, it is necessary to purchase products from trusted brands. We talked about it in a separate article.
Based on this, we can conclude that the color temperature of LED lamps is considered one of the main indicators in modern lighting. If this is not taken into account, the lighting system will be ineffective and unpleasant.
If the room is used for various purposes, then there are separate recommendations with which you can choose the most optimal lighting option. For example, it is better to equip the living room, bedroom and children's room with sources that will emit warm light.
So we looked at what the color temperature of LED lamps means and which is better for a home, apartment or office. We hope the tables and tips provided helped you decide on the most optimal characteristics!
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In lighting technology, color temperature is the most important characteristic of light sources, determining the color of the lamps and the color tone (warm, neutral or cold) of the space illuminated by these sources. It is approximately equal to the temperature of a heated body of the same color as a given light source. Color temperature is measured in degrees Kelvin (K). In practical lighting engineering, it is useful to associate the color temperature reproduced by artificial light sources of various types with natural light sources.
The color temperature scale is divided into three ranges: warm white, neutral white (natural) and cool white.
The sun, a natural source of light, has a very high physical temperature, but the equivalent color temperature of the light we receive at the Earth's surface fluctuates depending on the time of day and weather conditions. This occurs as a result of the reflection and refraction of light in the atmosphere.
We provide you with a comparative table of natural and artificial light sources:
Warm white
1850 - 2000 K
Sources of artificial lighting that reproduce this color temperature are the flame of a stearin candle. The natural light source is the morning or evening twilight sky (2000 K).
2000 – 2700 K
Sources of artificial lighting that reproduce this color temperature are incandescent lamps up to 40 W, high-pressure sodium lamps (HPS). Natural light source - the sky near the rising or setting Sun (2300 - 2400 K)
2700 - 2800 K
Artificial lighting sources that reproduce this color temperature are 60W incandescent lamps, mains voltage halogen lamps, fluorescent lamps (FL), compact fluorescent lamps (CFL), light emitting diodes (LED).
2800 - 3500 K
Artificial lighting sources that reproduce this color temperature are incandescent lamps 75-500W, mains voltage halogen lamps, low-voltage halogen lamps, LL, CFL, LED.
3500 K
Sources of artificial lighting that reproduce this color temperature are mains voltage halogen lamps, low-voltage halogen lamps, LL, CFL, metal halide lamps (MHL), LED. Natural light source – Sun one hour after sunrise/before sunset
The sensitivity of the human eye to the perception of color temperature is non-linear. A 500K difference in the warm part of the color temperature range is more noticeable than the same difference in the cold part of the range, so light source manufacturers offer a larger range of lamp colors in the warm range.
Neutral white
 |
4000 K Sources of artificial lighting that reproduce this color temperature - LL, CFL, MGL, LED / LED. Natural light source – Moon (4125 K) |
Cool white 
5000 K
Sources of artificial lighting that reproduce this color temperature - LL, CFL, MGL, LED / LED. A natural source of light is the morning or evening Sun in a clear sky at an angle of more than 15 degrees above the horizon (3600 - 5000 K).
5500 K
Sources of artificial lighting that reproduce this color temperature - LL, CFL, MGL, LED / LED. The natural source of light is the Sun around noon with light clouds (5100 -5600 K).
6500 K
Sources of artificial lighting that reproduce this color temperature - LL, CFL, MGL, LED / LED. A natural source of light is the summer Sun at its zenith in a clear blue sky (6000 - 6500 K).
7000 K
Sources of artificial lighting that reproduce this color temperature - MGL, LED / LED. The natural source of light is daylight from the sky with high, light clouds (6700 -7000 K).
12000 K
The natural light source is daylight from the sky with light clouds (12,000 - 14,000 K). The color temperature of a clear blue sky is 15,000 – 27,000 K.
William Kelvin, a British physicist, discovered in the late 19th century that a cube of coal, when heated to different temperatures, glows in different colors, ranging from deep red throughout the visible spectrum.
The color temperature of the sky on a cloudy day ranges from 6000 to 7500°K. This doesn't mean the sky is that hot. Color temperature indicates to what temperature Kelvin would have to heat his black carbon cube to cause it to emit the appropriate hue of color. So it's just a convenient way to quantify color in a way that everyone can understand.
The Kelvin temperature scale, unlike the Celsius and Fahrenheit scales, starts at “absolute zero,” the theoretical temperature at which molecular motion should cease completely.