What is the color temperature of light and the nuances of choosing the temperature of the lamps to suit your needs

LED lightening

LED lighting is one of the most common types of lighting fixtures. The color temperature of diodes is characterized by three main shades:

1. White in warm colors (abroad referred to as Warm White) - up to 3300 K.
2. Natural white (Neutral White) - up to 5000 K.
3. White in cold range (Cool White) - more than 5000 K.

The temperature characteristics of LEDs largely determine the scope of their application. First of all, diodes are used in street lighting, advertising billboards, as well as in automotive lighting.

Note! The color temperature of the diodes allows not only to set the contrast, but also makes it possible to determine how the light will be perceived when the weather changes.

White light in cold colors

Sunlight is the most accurate. For other light sources, significantly lower rates are characteristic. For example, for most LED lamps, the temperature indicator is in the range of 5000-8000 Kelvin. The average transfer rate for the corresponding index does not exceed 65 units.

The advantages of light sources in cold colors include their high contrast, which is very good when illuminating dark objects. LEDs, due to their ability to operate over long distances, are the best choice for lighting the road surface.

Neutral and warm light

It should be borne in mind that cold shades most distort the perception of colors. A cold color is characterized by sharpness, due to which contrast is achieved, but this is harmful to the human eye.

Warm gamma is less irritating to vision.In the range of 2500-6000 K, the color rendering index rises to 75-80 units, and such lighting devices show excellent results at short distances. Warm and neutral tones show a clear advantage when lighting in bad weather. For example, precipitation has a significant effect on the quality of cold light, while rain or snow is insignificant for warm shades. The reason is that warm sources allow you to see not only the object itself, but also the space around it. By the way, for the same reason, warm colors are more effective underwater.

Note! Energy-saving light bulbs have a warm spectrum. This is good, since cold gamma is of little use for residential lighting.

Lamp color temperature

The color temperature of lighting lamps is not necessarily the actual heating temperature of the lamp itself, which is felt tangibly. We can talk about the real temperature relative to the color temperature of the lamps, meaning only the heating of the filament of incandescent lamps. Even in this case, it is possible to change the color temperature of the lamp without changing the heating temperature of the coil. For example, you can use a colored glass filter. It will bend the radiation of the lamp, and thereby change the length light wave and color temperature. An example of the glow of a heated absolutely black body is only a template of a person's color perception of light radiation from various sources, and not necessarily lighting lamps.

The color temperature of lighting lamps, in principle, can be anything. ranging from red to purple. regardless of whether it is a lamp: fluorescent, induction or LED.For example, it is generally believed that the color temperature of incandescent lamps is 2200-3000 K. And fluorescent lamps are 3500-7000 K. But these types of lamps also exist with a color temperature of 20,000 K, which turns into ultraviolet. This also applies to other types of lamps, for example, LEDs.

Additional options for choosing a lighting lamp

When choosing a lighting lamp, you need to consider various additional parameters. Firstly, it is worth considering in what colors the design of the room illuminated by it is made. Secondly, for what purpose is the room intended. Thirdly, in what geographical region is this room located. As well as some other configurations. For example, for many people, the light of a cold white lamp may be associated with a surgical operating room. Of course, this causes an unsettling feeling. It also depends a lot on the geographical location. For example, in the northern regions there is a short summer period and low solar illumination. As a result, the light of such a lamp is likely to be perceived by a person most negatively. In the southern latitudes, with an excess of sunlight, on the contrary, it is pleasant and restful for the eyes.

When choosing a lamp with a certain color temperature, you must also consider the color rendering index. It shows how accurately the light of this lamp conveys the color gamut to our vision. That is, how natural the surrounding objects illuminated by this lamp are perceived. Or vice versa, not natural. So it all depends on what we want to achieve by using this or that lamp.

You can read posts on similar topics under the heading - Lighting

Your Comfortable Home

What is color

As strange as it may sound, light has its own color temperature! Lamps and lighting devices are installed in your apartment, house, office or grocery supermarket across the street.

And your perception of objects and even your mood depends on what color temperature they have. Let's take a look at these digital values, how many Kelvins what kind of glow.

1. 2700 K - in the people it sounds like a warm glow or warm white.
2. 4000-4200K is naturally white, although many consider it to be a cold white or cold glow, although this temperature is closest to the morning and afternoon sun.
3. 5500-6000 K - bright white or close to daylight.

In the interior and exterior, different types of lamps are used, based on the tasks, conditions and personal preferences of a person.

In classical interior design, warm or warm white light (2700 K) is mainly used. For these needs, LED lamps are ideal. In the color temperature column, check the "warm glow" box.

For a rapidly developing world, a glow temperature of 4000-4200 K is more and more suitable, so naturally white light is used in Hi-tech design interiors.

For offices, conference rooms, laboratories and for other high-precision work performed indoors, use bright white from 6000 K and above.

warm light how many kelvins

Warm orange: 2500-3000 Kelvin - will help create a cozy evening atmosphere in the bedroom and living room. It is used in floor lamps, sconces, bedside lamps, to illuminate the dining table. Warm yellowish: 3000-4000 Kelvin - relaxing and comfortable light for living rooms. Usually used in wall and ceiling lamps.

cold white light how many kelvins

Cool white - a color temperature above 5300 K. If daylight is more appropriate in the workplace (approximately 4000-4500 K), then colder white light is useful for reading (but only up to 6500 K).

2700 Kelvin what kind of light

The color temperature of a conventional incandescent lamp is approximately 2800 Kelvin, so the warm-white light of the glow of LED lamps is most familiar to the eye (from 2700 to 3500 K).

Color temperature 4000 K - what color is it

4000-4200K is naturally white, although many consider it to be a cold white or cold glow, although this temperature is closest to the morning and afternoon sun.

4300 Kelvin color

4300-4500 K - morning sun and afternoon sun. If we talk about cars, standard xenon, which is installed directly at the factory, has a glow color of 4300 Kelvin. When replacing car lamps in order to maximize the best visibility, experts advise installing xenon with a color of 4300 K.

6000 Kelvin what kind of light

The color of the radiation at 6000 K becomes bluish. This is how a fluorescent lamp with a daylight color of 6000 K shines.

6500 Kelvin what kind of light

6500 K is a standard daylight white light source, close to midday sunlight. For the working kitchen area, it is recommended to use cold light bulbs (above 6500 K), such light will invigorate.

Designations and numerical indicators

The color temperature is measured in Kelvin, denoted by the letter "K" and varies greatly depending on different parameters.The lowest values ​​are for the orange and red glow, the sun at sunset, for example (up to 2000K), and the highest for the blue sky and snow-white expanses - over 7000K. The division of lighting into 3 groups occurs in this way:

Warm, or yellowish, light comes from fire, tungsten lamps, and the sun at sunset. It is in the range from 1000 to 3500K: a candle or fire will give 1000-2000K, incandescent lamps a little more - about 2400-2800K, and sunlight at the beginning or end of the day will already give 2900-3500K, closer to neutral. Naturally, this is not a constant, the indicators will depend on a list of factors: weather, season, cloudiness and other points.

Neutral, or white, light does not affect color rendering and is ideal for photography. Of course, if the author does not intend to use the properties of lighting for artistic purposes. Light in the range of 4000-6500K is considered conditionally neutral. This includes a sunny day without clouds in the summer (4000-5000K), and cloudiness (about 5500K), and a standard flash on the camera (6000-6500K). It is neutral light that is most often used in photography in the genres: portrait, still life, subject. Yes, and "landscapers" are trying to catch the moment when the sun is at its zenith, especially when shooting architecture and urban panoramas.

The cold, or bluish, color of the lighting immediately gives rise to images of a snow-covered plain and fir-trees covered with "caps" on the outskirts of the forest. And everything is bathed in blue light. This is what it looks like in cold light. It has indicators in the range of 6500-20000K.And cold light includes: strong cloudiness or cloudy rainy weather (6500 - 7500K), the time after sunset when the sky loses its golden hue and turns blue (7500-8000K). And the clear winter sky shines the coldest, depending on the place, the figure can vary from 9000 to 15000K.

It is extremely important for the photographer to understand what kind of lighting he will have to use in shooting, then the output will be quite tolerable, and sometimes surprisingly successful shot. For convenience, all types of light sources and their temperatures are shown in the table:

color temperature scale

Today's domestic market offers a huge range of light sources on LED crystals. All of them work in different temperature ranges.

Usually they are chosen depending on the place 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 in it.

For optimal use of 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, just 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 color gamut, due to which the independent choice of optimal lighting has become more complicated, and all its shades have become determined by the material from which the semiconductor was made.

Color rendering index of LED lamps

The color rendering index characterizes the ability to perceive color gradations. When the light temperature of LED lamps is below 3200 K, color perception is significantly reduced. Try by candlelight to pull green or brown out of a box of colored pencils. Believe me, the task will not be easy.

The color rendering index is very clearly regulated for automotive LED lamps, because with poor color rendering, a situation may arise when the driver cannot distinguish between the roadbed and the roadside.

Light can change the brightness and saturation of colors in a room. This phenomenon is called metamerism.

Each lamp has a certain color rendering, which is indicated on the packaging with the index Ra (or CRl). This source parameter is determined by its ability to reproduce the colors of the illuminated object as accurately as possible.

You will achieve the best result using lamps with a color rendering index of 80 Ra and above. This will allow all interior colors to look most natural.

Characteristic	Coefficient	Lamp examples
Reference	99–100	Incandescent lamps, halogen lamps
Very good	Over 90	Fluorescent lamps with a five-component phosphor, MHL (metal halide) lamps, modern LED lamps
Very good	80–89	Fluorescent lamps with three-component phosphor, LED lamps
Good	70–79	Fluorescent lamps LBTs, LDTs, LED lamps
Good	60–69	Fluorescent lamps LD, LB, LED lamps
Mediocre	40–59	Lamps DRL (mercury), NLVD with improved color rendering
bad	Less than 39	Lamps DNAt (sodium)

Different types of lamps, having the same color temperature, can render colors differently. The color rendering index determines the degree of deviation of the color of interior items from its real color when illuminated by a particular lamp.

The difference between LED lamps

Between themselves, LED products differ in color temperature coefficient. To date, all products, regardless of the purpose (street, house, car) are divided into three main groups according to the range of luminescence:

• range within 2700-3500K. Such products emit a white warm light, which is very similar to the glow of incandescent lamps. Used for living quarters;
• range within 3500-5000K. This is the so-called neutral range. The glow here is called "normal white". The light emanating from the sweets operating in this range is reminiscent of sunlight in the morning. Suitable for technical premises at home (bathroom, toilet), offices, educational premises;
• range within 5000-7000K. The light emitted in this range is called "cool or daylight white" light. It corresponds to bright daylight. It is used for street lighting of parks, alleys, parking lots, billboards, etc.

Different lighting of lamps

If the color temperature does not match 5000K, shades, with the exception of white, will have warm tones (when this value is exceeded) or cold tones (when this value is reduced). At the same time, the housings of the light sources do not heat up, which does not in the least affect the service life of these energy-saving light bulbs.
Remember, when choosing such lighting products, it is imperative to give preference to the most appropriate color rendering index.

Which light is better - warm or cold?

At first glance, the answer to this question is obvious: with warm lighting it is more comfortable, which means it is better. But not everything is so simple. Illuminate the picture hanging in your bedroom, first with a warm, then a cold lamp, and then just take it out into the midday daylight. Amazing, right? Three different pictures. Almost everything has changed: from contrast and brightness to color reproduction. Even the facial expression has changed if it is a portrait.

Now suppose that your workplace is flooded with a warm spectrum. How well can you work if you constantly want to relax or even sleep? How much can a security guard see if searchlights cast a soft, warm light on an object? No brightness, no contrast. On the other hand, eyes get tired quickly when reading from the cold spectrum, and in the bathroom you don’t want to undress, but, on the contrary, put on a coat.

Where to use cold lamps

Cold light has a temperature of 5,000 degrees Kelvin and above. This is perhaps the most “indigestible” range for everyday human life, since before the advent of artificial sources, we almost never encountered it. The cold spectrum is associated with cold, it quickly tires the eyes when reading and working with small objects. Colors fade in this light, and the objects themselves look brighter and more contrasting. A person in a room with cold lighting feels uncomfortable, he is “chilly”, he is constantly collected and focused. The cold spectrum can be called rather technical, and it is better to limit its use to the following options:

• general lighting in the office;
• careful local illumination of the bathroom (shaving, washing), a workplace in the kitchen, in the office;
• lighting of technical and office premises (storerooms, stairwells, corridors, etc.);
• local decorative illumination of strict interiors;
• illumination of objects of observation;
• street lighting.

Neutral (natural) light

Neutral light (also called natural) has a color temperature of 3,500 - 5,000 K and is the most familiar to our eyes. Radiation of this type is pure white and most closely matches natural light - the light of the sun on a clear noon. Neutral light does not distort colors and preserves the natural brightness and contrast of objects. It does not tire the eyes and does not create any subjective sensations of heat or cold. Neutral light lamps can be used in almost all residential areas, but the following options will be especially useful:

• main light in the nursery and local lighting of play and study areas;
• office, including local illumination of the workplace;
• place for reading;
• working area of ​​the kitchen;
• make-up table
• local lighting of mirrors;
• hallway.

Where is the best place to use warm lamps

Warm light, the color temperature of which lies in the range of 2700 - 3500K, as noted above, is distinguished by the presence of a soft yellowish tint. Objects in this spectrum appear to have less contrast, and colors appear more saturated. Due to the peculiarities of our eyes, warm light at the same radiation intensity appears dimmer than cold light. But on the other hand, it creates comfort, is especially pleasing to the eye and has a calming effect.In what situations would warm lighting be most preferred? You will be surprised, but there are many places where warm spectrum sources are preferable to neutral ones:

• general lighting in the living room;
• bedroom;
• canteen;
• general bathroom lighting;
• local lighting of recreation areas;
• night and emergency lighting, floor lamps;
• illumination of personal plots and arbors.

To warm light, as well as to neutral, we are accustomed to since childhood. The light bulbs of Ilyich, well known to you, which have been widely used in residential premises since a dozen years ago, emit just such a spectrum.

Color temperature specifications

Color rendering index

This is another characteristic of light bulbs that directly affects the comfort of staying indoors.

Have you ever noticed that things are perceived differently in a store, at home or under the light of lanterns? The question is not only the level of illumination, but also the color rendering index. This parameter is responsible for how natural the colors will look.

The color rendering index is measured in Ra (or CRl). The closer the color temperature to 5000 K, the more balanced the composition of the light and the closer it is to the ideal "white" color of the sun. When the color temperature is lowered, the proportion of red increases and the proportion of blue decreases. That is why incandescent lamps with DH 2000-3000 K give everything around a reddish tint. Conversely, LED lamps with a color temperature above 5000 K can give things a greenish or bluish tint.

For home use, it is recommended to buy light bulbs with a color temperature of 80 CRl and above. For auxiliary light bulbs with 60-80 CRl are suitable.

color temperature scale

All shades of color temperature are usually marked on a scale.

• The black body has zero color temperature. The first visible radiations appear at a color temperature of 800 K.
• The bright red color observed when some metals are heated corresponds to a CG of 1300 K.
• A candle or hot coals gives a color temperature of 2000 K.
• At sunrise, a color temperature of 2500 K is observed.
• Conventional incandescent lamps have a color temperature of 2700-3200 K.
• White color has a CG of about 5500 K. This is the color of the sun at noon.
• A cloudless blue sky has a color temperature of 7500 K.

Color temperature marking

Color temperature is measured in Kelvin (K), but light bulb manufacturers do not always use numbers. Quite often you can find inscriptions describing the color temperature:

1. WW (warm write) - warm shades, their color spectrum is 2700-3200 K.
2. NW (neutral white) - neutral colors with CG 3200-4500K;
3. CW (cool white) - cold white color with radiation from 4500 K.

Features of diode light

A light emitting diode is a semiconductor device that emits light when an electric current is passed through it. The light that such a diode is capable of emitting is located in a rather 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:

• combination of diodes of different colors of glow in order to obtain white light. This method allows you to get 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 for coating diodes.This is a fairly cheap and profitable method that allows you to achieve a higher color rendering index. But here, due to the applied phosphorus coating, there is a decrease in luminous efficiency.

The structure of the lamp

An LED light bulb consists of several diodes at once, 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 direct current, which is necessary to power the diodes. Due to this structure, these light sources create a directional light flux, which is characterized by a directivity angle for the generated glow.

What is a color rendering index?

Light can change the brightness and saturation of colors in a room. This phenomenon is called metamerism.

Each lamp has a certain color rendering, which is indicated on the packaging with the R index._a (or CRL). This source parameter is determined by its ability to reproduce the colors of the illuminated object as accurately as possible. You will achieve the best result using lamps with a color rendering index from 80 R_a and higher. This will allow all interior colors to look most natural.

Characteristic	Coefficient	Lamp examples
Reference	99–100	Incandescent lamps, halogen lamps
Very good	Over 90	Fluorescent lamps with a five-component phosphor, MHL (metal halide) lamps, modern LED lamps
Very good	80–89	Fluorescent lamps with three-component phosphor, LED lamps
Good	70–79	Fluorescent lamps LBTs, LDTs, LED lamps
Good	60–69	Fluorescent lamps LD, LB, LED lamps
Mediocre	40–59	Lamps DRL (mercury), NLVD with improved color rendering
bad	Less than 39	Lamps DNAt (sodium)

The color temperature of the light source and the perception of its shades

By combining light sources with different temperatures within the same room, you can change the color perception of objects in the interior

But don't get carried away! It is important to monitor the harmony of colors, otherwise you may end up with a “color disco” that will irritate your eyes. Yes, and unsuccessful lighting design will show the taste of the owner of the apartment not from the best side

• The red color can be softened with a warm orange tint of light (2500–3000 K).
• Orange color (intense) turns into a delicate and pastel color with a warm yellowish tint (3000-4000 K).
• The yellow color will become gray and inexpressive if you use lamps with a bluish tint (5000-6500 K).
• Greens can be softened to light green with warm orange light, or they can be tinted aqua with bright bluish light.
• Blue color can be most adequately conveyed by light sources of a neutral white hue.
• Violet color with a yellowish tint of lighting will turn into red, so it is illuminated with a high color temperature.

By making a mistake when choosing a lamp of a certain color temperature, you can significantly change the color perception of the interior.

Choosing LED lamps for the home

Warm white light: color temperature 2700-3200K

Lamps with such light are best suited for areas intended for relaxation. For example, such a light would be good to use in the bedroom.

In the living room, it would be ideal to install lamps in which warm light is combined with neutral. Then, while reading, receiving guests, communicating with loved ones, it will be possible to turn on neutral light, and while watching TV - warm.

Neutral white light: 3200-4500K

This color temperature is great for doing current affairs. For example, the hostess will feel comfortable cooking, the child will study, and the adult members of the family will read. It is the neutral white lamps that are the most versatile, and if you are not sure which one to choose in the store, give preference to this particular category.

Cool white light: color temperature over 4500K

Use cold white light at home as carefully as possible. It helps to concentrate, but negatively affects the nervous system with prolonged use. We would recommend installing cool white light bulbs in table lamps in the classroom or on the student's desk to use for several hours during work or class. And even in this case, the color temperature of the bulbs should not exceed 5000 K.

Features of color perception

In everyday life, the concept of light temperature is used in interior design, selection of lamps for offices, production workshops, etc. It has been proven that a person reacts to a change in illumination - in some cases, activation of activity is observed, in others, on the contrary, relaxation of the body.

CG and color rendering index

The quality of lighting is of great importance to the color rendering coefficient - Ra or CRL. The parameter determines the ability of the light source to convey the clarity of objects, namely, the realism of the illuminated object.

The index is indicated in absolute terms, the maximum value of Ra is 100. The reference indicator is natural sunlight

The highest color rendering for incandescent lamps and halogen lamps, the Ra parameter is 99-100.

In everyday life, lighting devices with indicators have found application:

• 100˃Ra˃90 - excellent light transmission properties are characteristic of fluorescent bulbs with a five-component phosphor, LED and metal halide lamps;
• 89˃Ra˃80 - LED lamps, fluorescent devices equipped with a three-component phosphor;
• 80˃Ra - low color rendering quality; can be used in utility rooms, corridors or for road lighting.

When choosing a lamp, it is important to consider that devices with the same light temperature can differ significantly in color quality. Before buying, it is worth comparing both parameters

The combination of characteristics is given in the table. Communication lines indicate the numerical value of the CG of a certain type of lamp and the range of the color rendering index

In everyday life, you should not use devices with an Ra value of less than 80. Lamps with a maximum degree of color rendering are suitable for framing and illuminating a mirror.

The effect of light on emotions

The spread of LED technologies, a variety of shapes of lamps and chandeliers allows not only to reduce energy costs, but also to match the shade of LED bulbs to the functions of the room.

This aspect has a noticeable effect on the well-being of people, activates the brain, increases productivity, or, on the contrary, promotes rest and relaxation.

The impact of lighting on humans:

• bright warm light invigorates, helps to wake up faster in the morning, and in the evening sets in a calm mood;
• a cold shade increases concentration, but its constant exposure is tiring and leads to insomnia;
• intense lighting activates the work of the body;
• warm tones help to relax, unwind and fall asleep.

To increase the comfort of living, improve working conditions, dynamic solutions are being developed - lighting systems focused on human needs.

These are complex lighting systems that change brightness, color temperature and other lighting parameters during the day according to a given algorithm.

Such solutions are being implemented in European countries and the United States in the construction of hospitals, offices, industrial and residential premises.

Relationship between lighting and DH

Research by the Dutch physicist Kruithof (Arie Andries Kruithof) confirmed the relationship between color temperature and light intensity.

For example, a lamp with a CG value of 2700 K, emitting a luminous flux of 200 lx, creates a comfortable light. However, a table lamp with twice the power and the same color temperature appears too yellow and quickly becomes annoying.

The scientist developed a graph, the so-called comfort curve - it determines the areas of low and high levels of illumination at different DH, providing the most comfortable stay for a person

The optimal color temperature is perceived as a white glow and feels close to natural sunlight.

Some lighting manufacturers offer customizable fixtures. And engineers optimize light brightness and color temperature. The user chooses the most convenient mode on his own.

The main light is bright lighting with a cool tone, it sets you up for work, helps you concentrate. Soft backlight - a warm, dim glow for relaxation before bedtime, easy communication

The combined version resembles daylight, has a neutral effect on a person and is suitable for everyday activities.