CRI and color temperature

CRI = Color Rendering Index

Color rendering, expressed as a rating from 0 to 100 on the Color Rendering Index (CRI), describes how a light source makes the color of an object appear to human eyes and how well subtle variations in color shades are revealed. The higher the CRI rating is, the better its color rendering ability. CRI should be over 80 to reach the good results.


Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that light source. The temperature is conventionally stated in units of absolute temperature, known as Kelvin (K).

Understanding the color of light, also known as Kelvin temperature (K), can make it easier for you to choose lighting that will give you the effect you want.

Warm white up to 3000 K is calm, relaxing light for use in any room. Perfect for use in bedrooms, living rooms, dining rooms and restaurants.

Cool white 3100 – 4500 K. Produces a friendly, inviting light for use in any room. Ideal for use in basements, garages and work environments.

Daylight 4600 – 6500 K. Produces a crisp, vibrant light for use in any room. Recommended for display areas, security
lighting and garages.

This picture explains much more.


LED vs traditional lamp.

One of the best comparison you can find HERE

After investment you can start saving on electricity and also maintenance cost. The lifespan of LED lamps use to be significantly longer than other alternatives, also no harmful materials, bright light immediately without delay.

Benefits of LED

1. Long life time stands out as the number one benefit of LED lights. LED bulbs and diodes have an outstanding operational life time expectation of up to 100.000 hours. This is 11 years of continuous operation, or 22 years of 50% operation. If you leave on the LED fixture for 8h per day it would take around 20 years before you’d have to replace the LED bulb.

2. Energy efficiency

Todays most efficient way of illumination and lighting, with an estimated energy efficiency of 80%-90% when compared to traditional lighting and conventional light bulbs. This means that about 80% of the electrical energy is converted to light, while a ca. 20% is lost and converted into other forms of energy such as heat.With traditional incandescent light bulbs who operate at 20% energy efficiency only, a 80% of the electricity is lost as heat.

3. Ekologically friendly

LED lights are free of toxic chemicals. Most conventional fluorescent lighting bulbs contain a multitude of materials like e.g mercury that are dangerous for the environment.

LED lights contain no toxic materials and are 100% recyclable, and will help you to reduce your carbon footprint by up to a third. The long operational life time span mentioned above means also that one LED light bulb can save material and production of 25 incandescent light bulbs. A big step towards a greener future!

4. Durable quality

LEDs are extremely durable and built with sturdy components that are highly rugged and can withstand even the roughest conditions.

Because LED lights are resistant to shock, vibrations and external impacts, they make great outdoor lighting systems for rough conditions and exposure to weather, wind, rain or even external vandalism, traffic related public exposure and construction or manufacturing sites.

5. No UV emissions

LED illumination produces little infrared light and close to no UV emissions.

Because of this, LED lighting is highly suitable not only for goods and materials that are sensitive to heat due to the benefit of little radiated heat emission, but also for illumination of UV sensitive objects or materials such a in museums, art galleries, archeological sites etc.

6. Design possibilities and flexibility

LEDs can be combined in any shape to produce highly efficient illumination. Individual LEDs can be dimmed, resulting in a dynamic control of light, color and distribution. Well-designed LED illumination systems can achieve fantastic lighting effects, not only for the eye but also for the mood and the mind:
LED mood illumination is already being used in airplanes, classrooms and many more locations and we can expect to see a lot more LED mood illumination in our daily lives within the next few years.

7. Operational temperatures

LED are ideal for operation under cold and low outdoor temperature settings. For fluorescent lamps, low temperatures may affect operation and present a challenge, but LED illumination operates well also in cold settings, such as for outdoor winter settings, freezer rooms etc.

8. Low voltage

A low-voltage power supply is sufficient for LED illumination. This makes it easy to use LED lighting also in outdoor settings, by connecting an external solar-energy source and is a big advantage when it comes to using LED technology in remote or rural areas.

LED And Design

LEDs give you wide freedom to create fascinating lighting. Here you can find some tips how to use LED lighting. Take a look at THIS and also Pinterest offers something good HERE.

Wofi has a good selection of various series. You can pick up the whole series including table lamps, wall lamps, pendants, ceiling lamps… or make a combination. Lighting and decorating indoors or outdoors Barthelme has solutions for you.

Architectural lighting design is a field within architecture and architectural engineering that concerns itself primarily with the illumination of buildings. The objective of architectural lighting design is to obtain sufficient light for the purposes of the building, balancing factors of initial and operating cost, appearance, and energy efficiency.

Comprehensive lighting design requires consideration of the amount of functional light provided, the energy consumed, as well as the aesthetic impact supplied by the lighting system. Some buildings, like surgical centers and sports facilities, are primarily concerned with providing the appropriate amount of light for the associated task. Some buildings, like warehouses and office buildings, are primarily concerned with saving money through the energy efficiency of the lighting system. Other buildings, like casinos and theatres, are primarily concerned with enhancing the appearance and emotional impact of architecture through lighting systems.

Good optics

With good optics you can increase the efficiency up to 10%. But also notice the light pollution and photobiological risk for human eye. Many manufacturer are not telling anything about these simply because they don´t have anything to offer in that. But the right optics with correct selected for the need of illumination is a good first step. Certification against photobiological risk and light pollution is the next one. It is easy to get a lot of lumens but distributing the light wherever around. Even fewer lumens but directed to needed area you can get more light where it is needed. It´s about optics! And it´s not only for street lights. Urban lighting is annoying if the glare effect is not controlled and the light distribution not comfortable for eyes. Disturbing neighbors or illuminating areas where the light is not needed or wanted. Once more, it´s about optics!