Add as home page    Add to your favourites    Hello,Welcome! 【Login】 【Register】
LED Australia

Releate Goods

                                                                         Your Position: Home > Articles > LED/Lighting Knowledge > How to apply the color temperature and color of the LEDlight

How to apply the color temperature and color of the LEDlight

Monika / 2013-02-28

Befor we talk about the applacations of the color temperature and color, we have to know what is color temperature?
Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, horticulture, 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 of the light source. In practice, color temperature is only meaningful for light sources that do in fact correspond somewhat closely to the radiation of some black body, i.e. those on a line from reddish/orange via yellow and more or less white to blueish white; it does not make sense to speak of the color temperature of e.g. a green or a purple light. Color temperature is conventionally stated in the unit of absolute temperature, the kelvin, having the unit symbol K..
colour temperature of sources: People use equal light color temperature of source or closely absolute temperature of perfect radiator to describe light color table (We see the light color when the human eye directly observed light source) also called light color temperature. Different color temperature can cause people emotionally different reaction, the light colour temperature is usually divided into three categories:
 
a> lower color temperatures (under 3,300 K) are called warm colors. Warm color light is nearly with incandescent light hue. The red light component is more. The warm color light gives a person with warm, healthy, comfortable feeling. Suitable for family, home, dormitory, hospitals, hotels and other low temperature places.
b> Color temperatures(3,300K-5,500K)are called warm white colors, also known as intermediate Color. The warm white light is downy, make the person pleasant, comfortable, peaceful feeling. Suitable in shop, hospital, office, hotel, restaurant, waiting room and other places.
c> Color temperatures over 5,300K are called cool colors (blueish white), also known as sun color. Light source is closed to natural light, bright feeling, make the person focus. Suitable for the office, conference room, drawing room, classroom, design room, library reading room, display window and other places.
Color temperature applications
For lighting building interiors, it is often important to take into account the color temperature of illumination. For example, a warmer (i.e., lower color temperature) light is often used in public areas to promote relaxation, while a cooler (higher color temperature) light is used to enhance concentration in offices.
Aquaculture
In fishkeeping, color temperature has different functions and foci, for different branches.
In freshwater aquaria, color temperature is generally of concern only for producing a more attractive display. Lights tend to be designed to produce an attractive spectrum, sometimes with secondary attention to keeping plants alive.
In a saltwater/reef aquarium, color temperature is an essential part of tank health. Within about 400 to 3000 nanometers, light of shorter wavelength can penetrate deeper into water than longer wavelengths (see Electromagnetic absorption by water), providing essential energy sources to the algae hosted in (and sustaining) coral. This is equivalent to an increase of color temperature with water depth in this spectral range. Because coral, typically living in shallow water, receives intense, direct tropical sunlight, the focus was once on simulating this with 6,500 K lights. Higher temperature light sources have become more popular, first with 10,000 K and more recently 16,000 K and 20,000 K. Meanwhile, actinic lighting is used to make the somewhat fluorescent colors of many corals and fish "pop", creating brighter "display" tanks
Digital photography
In digital photography, color temperature is sometimes used interchangeably with white balance, which allow a remapping of color values to simulate variations in ambient color temperature. Most digital cameras and RAW image software provide presets simulating specific ambient values (e.g., sunny, cloudy, tungsten, etc.) while others allow explicit entry of white balance values in kelvins. These settings vary color values along the blue–yellow axis, while some software includes additional controls (sometimes labeled tint) adding the magenta–green axis, and are to some extent arbitrary and subject to artistic interpretation.
Photographic film
Photographic emulsion film sometimes appears to exaggerate the color of the light, as it does not adapt to lighting color as human visual perception does. An object that appears to the eye to be white may turn out to look very blue or orange in a photograph. The color balance may need to be corrected while shooting or while printing to achieve a neutral color print.
Photographic film is made for specific light sources (most commonly daylight film and tungsten film), and used properly, will create a neutral color print. Matching the sensitivity of the film to the color temperature of the light source is one way to balance color. If tungsten film is used indoors with incandescent lamps, the yellowish-orange light of the tungsten incandescent lamps will appear as white (3,200 K) in the photograph.
Filters on a camera lens, or color gels over the light source(s) may also be used to correct color balance. When shooting with a bluish light (high color temperature) source such as on an overcast day, in the shade, in window light or if using tungsten film with white or blue light, a yellowish-orange filter will correct this. For shooting with daylight film (calibrated to 5,600 K) under warmer (low color temperature) light sources such as sunsets, candlelight or tungsten lighting, a bluish (e.g., #80A) filter may be used.
If there is more than one light source with varied color temperatures, one way to balance the color is to use daylight film and place color-correcting gel filters over each light source.
Photographers sometimes use color temperature meters. Color temperature meters are usually designed to read only two regions along the visible spectrum (red and blue); more expensive ones read three regions (red, green, and blue). However, they are ineffective with sources such as fluorescent or discharge lamps, whose light varies in color and may be harder to correct for. Because it is often greenish, a magenta filter may correct it. More sophisticated colorimetry tools can be used where such meters are lacking.
Desktop publishing
In the desktop publishing industry, it is important to know a monitor’s color temperature. Color matching software, such as ColorSync will measure a monitor's color temperature and then adjust its settings accordingly. This enables on-screen color to more closely match printed color. Common monitor color temperatures, along with matching standard illuminants in parentheses, are as follows:
5,000 K (D50)
5,500 K (D55)
6,500 K (D65)
7,500 K (D75)
9,300 K.
D50 is scientific shorthand for a Standard illuminant: the daylight spectrum at a correlated color temperature of 5,000 K. Similar definitions exist for D55, D65 and D75. Designations such as D50 are used to help classify color temperatures of light tables and viewing booths. When viewing a color slide at a light table, it is important that the light be balanced properly so that the colors are not shifted towards the red or blue.
Digital cameras, web graphics, DVDs, etc. are normally designed for a 6,500 K color temperature. The sRGB standard commonly used for images on the Internet stipulates (among other things) a 6,500 K display whitepoint.
TV, video, and digital still cameras
The NTSC and PAL TV norms call for a compliant TV screen to display an electrically black and white signal (minimal color saturation) at a color temperature of 6,500 K. On many consumer-grade televisions, there is a very noticeable deviation from this requirement. However, higher-end consumer-grade televisions can have their color temperatures adjusted to 6,500 K by using a preprogrammed setting or a custom calibration. Current versions of ATSC explicitly call for the color temperature data to be included in the data stream, but old versions of ATSC allowed this data to be omitted. In this case, current versions of ATSC cite default colorimetry standards depending on the format. Both of the cited standards specify a 6,500 K color temperature.
Most video and digital still cameras can adjust for color temperature by zooming into a white or neutral colored object and setting the manual "white balance" (telling the camera that "this object is white"); the camera then shows true white as white and adjusts all the other colors accordingly. White-balancing is necessary especially when indoors under fluorescent lighting and when moving the camera from one lighting situation to another. Most cameras also have an automatic white balance function that attempts to determine the color of the light and correct accordingly. While these settings were once unreliable, they are much improved in today's digital cameras, and will produce an accurate white balance in a wide variety of lighting situations.
Color rendering: Effect of an illuminant on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference illuminant. It is good for high color rendering of light source to the color performance, the color what we see is more close to natural color, it is poor for high color rendering of light source to the color performance, the color deviation what we see is also bigger.
 
Why is color rendering distinguished hight and low? The key lies in the light of the spectral characteristics. The visible light wavelength from 380 nm to 780 nm in the scope, is what we see in the spectrum of red, orange, yellow, green, blue, blue, purple light range. If the proportion of the light of the radiation from the light source is similar to natural light, then the color what our eyes can see is more vivid.
 
We think usually color rendering index for color rendering characterization.Color rendering index under standard color in radiation of standard light source is at 100. Requiremen of light rendering index in different places is not the same.In the international lighting association the color rendering index is generally divided into five categories:
 
Category Ra applicable scope
1 a > 90  art galleries, museums and printing and so on
2 b 80-90  family, restaurant, senior textile technology and similar industry
2 60 – 80 office, school, outdoor street lighting
3 40 - 60   heavy industry factory, outdoor street lighting
4 20-40   outdoor road lighting and some places with low requirement

Next: Led Lamp Previous: Low Heat Dissipation
LINK:
Home Company Profile Shipping & Freight info Payment Support Sitemaps

© 2005-2019 ALLED Copyright, All Rights Reserved.
Tel: 0285990000 E-mail: info@alled.com.au