CCT value represents the color of different kinds of light source; standard unit for color temperature is Kelvin (K). You can see the color of yellow stays between 3000 ~ 4000K and color while between 5000 - 6000K.
Any lamp or luminaire that is sold should have its CCT written on it. Commonly available CCT values are as follows:
-2700K – is widely used in residential situations, especially where people relax. Also popular in pubs and restaurants.
-3000K – is for general purpose residential use
-3500K – is sometimes used in commercial environments, especially where furniture and some luxury goods are sold
-4000K – is popular in offices classrooms and supermarkets. Also widely used in street lighting.
-5000K – is commonly used in commercial and industrial
-6000K – is often used in areas of high ceiling, such as warehouses or gyms.
The color rendering index (CRI) is a quantitative measure of the ability of an artificial light source to reproduce the colors of various objects faithfully in comparison with natural sunlight. Sunlight was defined as an ideal light source and having a CRI of 100.
When making CRI comparison for any kind of light source, suggest choosing the same color for the lights being compared, so it will be easier to determine the results.
For purchase and installation of white LED lights, we would recommend a CRI over 90. However, is some projects, a minimum of CR 85 is also acceptable. A brief explanation of CRI ranges are as follows:
-CRI 95-100 - Excellent colour rendering. Skin tones look stunning, subtle tones stand out and are emphasized, artwork comes to life, and paint and backsplashes display their real colours. It is commonly used in residential applications, high-end retail settings, printing and painting facilities, design hotels, and exhibition spaces where vivid natural colour are required.
-CRI 90 - 95 - Wonderful colour rendering. Nearly all colours stand out and are distinct from one another. At a CRI of 90, illumination becomes noticeably excellent. Your kitchen's newly placed teal backsplash will appear stunning, bright, and fully saturated. Visitors start complimenting your kitchen's counters, paint, and details, but they don't realize that the lighting is mostly to blame for its stunning appearance.
-CRI 80 - 90 - Most colours are portrayed well in good colour rendering. Suitable for the majority of commercial needs. It's possible that some details won't appear as saturated as you'd like.
-Lighting with a CRI of less 80 is regarded as having poor colour reproduction. When viewed in this light, objects and colours may appear dull, desaturated, and occasionally unrecognizable (for example, it could be difficult to distinguish between black and navy-coloured socks). It would be challenging to tell comparable colours apart.
See the Color rendering index sample as below on fruits.
Use of an artificial source of light for illumination. It is a key element of architecture and interior design. Residential lighting uses mainly either incandescent lamps or fluorescent lamps and often depends heavily on movable fixtures plugged into outlets; built-in lighting is typically found in kitchens, bathrooms, and corridors and in the form of hanging pendants in dining rooms and sometimes recessed fixtures in living rooms. Lighting in nonresidential buildings is predominantly fluorescent.
The CIE diagram, or more precisely the CIE Chromaticity Diagram, is shown below. It was created in 1931 by the Commission internationale de l'Eclairage.
Chromaticity is an objective specification of the quality of a color regardless of its luminance. Chromaticity consists of two independent parameters, often specified as hue (h) and colorfulness (s), where the latter is alternatively called saturation, chroma, intensity, or excitation purity. This number of parameters follows from trichromacy of vision of most humans, which is assumed by most models in color science.
Every sport events require good lighting to ensure the sports are played safely and to provide optimal visibility for participants and spectators. The criteria that are used to specify, create, and measure good lighting conditions for Sport lighting are as follows:
to view our document clearly.
- Horizontal Illuminance
- Vertical Illuminance
- Illuminance Uniformity
- Flicker Free
- Light Pollution
- Good lighting & quality
The quantity of light is measured in lux and the amount of light required depends on the sports played. The faster the sports and the smallest the playing object, the higher lux required. There are two types of illuminances such as horizontal illuminance.
Horizontal illuminance is a measure of light reaching a horizontal plane, one meter above the playing surface. A 10m x 10m grid across the playing field is used as a basis for collecting these measurements and calculating maximum/minimum/average illumination on the playing field
Average Maintained Horizontal Illuminance (Eh) is the average quantity of lux over the horizontal playing surface that serves to establish the adapted state of the eyes and acts as a visual background against which players and ball stand out, enabling them to be identified quickly and clearly.
Vertical illuminance is the light in the direction of a camera which is useful in creating a picture for a camera. Calculations and measurements shall be made 1 (one) meter above the pitch surface, in the direction of the camera. There are 2 type of camera vertical illuminance that should be assessed:
Field Camera Vertical - Vertical lighting at field level is the amount of illumination reaching the vertical surface of the players. This illumination helps to show close-up details of players, particularly their faces, at critical moments during the match. These images are captured by (both hand-held and motorized) field camera positions. Variations in vertical illumination will create poor digital video.
Fixed camera vertical - Vertical light above the pitch captured by the upper touch-line and goal-line cameras is referred to as fixed camera vertical illumination. These cameras panning the pitch must capture the entire play during the event. Variation in illumination will create poor digital video. The lighting designer must consider balancing the illumination to reduce these over- /under-illuminated areas during fixed camera operations.
An adequate level of uniformity is required to create a balance lighting conditions so that the viewers eyes and the television cameras do not have to continue adapting to the different light level. Uniformity is expressed in the ratio of the lowest to the highest illuminance (Emin/Emax) and the ratio of the lowest to the average illuminance (Emin/Eaverage).
In non-televised situations, horizontal brightness uniformity is typically specified between 0.5 and 0.7 (Emin/Eaverage) depending on the type of sport and lighting.
Meanwhile, in the televised situation, high uniformity is necessary to achieve smooth and natural shots. The horizontal brightness is generally 0.8 whereas the vertical brightness for fixed cameras is 0.7 (Emin/Eaverage). The illuminance uniformity for TV/film coverage at a certain grid point thus has to be expressed as a percentage change from the average adjacent grid points. This is called the uniformity gradient.
A common uniformity gradient value for both horizontal and vertical illuminance in the direction of main cameras of ≤20% on a 4m calculation grid might ensure smooth panning between one area to another.
Sport Lighting system should be designed to minimize glare so that the vision of players and spectators will not be affected. Glare is caused by the difference (contrast) between the direct brightness of the installation (entering a person eye) and the brightness of the pitch. When the ratio of these two brightness is too high, this will cause visual disability or discomfort. One of the most effective ways to control glare is to select appropriate mounting heights and positions of equipment around the pitch. Glare Ratings should not exceed GR < "50" for any position on the pitch.
The most significant change has been with the use and coverage of events by slow motion and hi-motion cameras with the right flicker free lighting. Broadcasters are looking to create imaginative and exciting flicker free images. To avoid and visible slow motion image flicker, a flicker factor of less than 3 percent is recommended.
Spill illumination leaving the stadium can be calculated and measured. These values are expressed in horizontal illumination values and maximum vertical illumination.
A suitable range of color temperature should be ≥ 5700K for outdoor facilities
Color rendering describes the capacity of a light source and excellent color rendering is CRI ≥ 90
Percentage (90%) of light emitted from the luminaire compare to total input power