Jun. 10, 2024
A colour selectable lamp or Light fitting is one in which the corelated colour temperature (CCT) of the light generated can be selected from a small number of fixed options.
CCT is measured in kelvin (K) and describes if a white light is warm (with a slight yellow hue, around K), neutral (around K) or cool (with a slightly blue hue, starting from around K). For more details, "What is correlated temperature CCT ?". CCT applies to white light only.
Note that colour selectable is also known as field-selectable CCT and CCT colour switching,
Frequently, lighting manufacturers will produce a popular design of luminaire that could be used in different settings &#; for example in an office and in the home. However, in an office people will usually expect a CCT of K-K (&#;cool&#; white), while at home they might prefer K or K (&#;warm&#; white).
To save the manufacturer (and the entire supply chain) from having to stock multiple versions of the same product they produce &#;colour selectable&#; fittings. These feature a switch on the product itself that allows the installer to choose from a small range of pre-set colour temperatures, so that the same fitting can be used in multiple different settings.
Colour selectable fittings are also beneficial in that they allow the end-user the opportunity to change their mind and alter the colour temperature after installation without having to change the complete fitting.
All LEDs can produce just a single colour of light. Therefore, a colour selectable light fitting contains two or more separate arrays (or groups) of LEDs, with each LED array producing a different colour temperature. A switch, often located on the rear of the fitting, is used to determine which array of LEDs is to be powered on at any one time. Commonly, a colour selectable light fitting will offer a choice of just two CCT values (eg K and K), though others offer a choice of three CCT values.
Note that colour selection is static. With a colour selectable fitting there is no means (short of accessing the rear of the fitting and adjusting a switch) to change the colour temperature of the white light that is being produced.
&#;Colour selection is usually made with a switch on the rear of, or inside, the light fitting&#;
Colour selectable lighting relates to white-light fittings. A colour selectable fitting allows the installer or user to select the correlated colour temperature (CCT) of the light the fitting will produce from a small number (usually 2 or 3) of fixed options. Typical options could be warm-white (K), neutral white (K) or cool white (K). Colour selectable lighting is widely used in residential and commercial projects such as offices and shops.
Colour changing lighting is LED lighting that can create a very wide range of different colours which can be changed dynamically. Colour changing lighting is often used on building facades and on feature walls in clubs and bars. The colours can be continually changing, usually controlled by a DMX control system.
CCT and CRI are both important measures of the quality of white light.
CCT (correlated colour temperature) defines how the light appears and how it might make us feel. A low CCT value (eg K) indicates that the light contains a substantial proportion of the red, orange and yellow wavelengths, which we often call &#;warm&#; white. A higher CCT value (eg K) would have less red and orange but more of the blue wavelengths, which we would call a &#;cool&#; white.
With CCT it is not accurate to claim that one value is better than another. If we prefer warmer or cooler whites is generally a matter of personal preference.
CRI (colour rendering index) defines how well a particular white light enables us to perceive the colour of the objects it illuminates.
The colour of the objects we see is a result of the wavelengths of light that land on them and which are subsequently either absorbed or reflected. We perceive grass to be green because even though daylight (which contains red, orange, yellow, green, blue etc wavelengths) is shining onto it, all the other wavelengths are absorbed and only the green wavelengths are reflected.
However, grass can only appear green if the white light shining onto it contains green wavelengths in the first place. If any wavelength is missing from a beam of white light then an object that should be that colour will not appear so under that particular beam of light. Grass that should be green, seen under a light source that is missing some green wavelengths, will appear to be dull, and in extreme cases, even grey in colour.
Daylight has a CRI of 100 because it contains at least some of every single one of the visible wavelengths. A good quality artificial white light that enables us to see colours well will have a high CRI, above 90. This would normally be required in a shop &#; especially one selling clothes. A CRI>80 is generally required in offices and classrooms. A CRI>70 is suitable in many exterior applications, such as street lighting, but any CRI lower than 70 is generally not acceptable in any setting.
Unlike CCT (where there is no objective &#;better&#; or &#;worse&#; CCT value), CRI is objective. High values are better and lower values are worse.
Back to Technical Support
Our A19 and A21 lamps fit in standard lamp fixtures and are perfect for floor and desk lamp fixtures.
Our candelabra LED bulbs offer soft and warm light output in a decorative bulb style that fits E12 lamp fixtures.
BR30 lamps are ceiling lamps that fit in residential and commercial fixtures with 4-inch or wider openings.
Directly replace 4-ft fluorescent lamps with our T8 LED tube lights, compatible both with and without ballasts.
LED tube light fixtures pre-wired and compatible with our T8 LED lamps.
Linear lamp fixtures in 2-ft and 4-ft lengths. Plugs into standard wall outlets nd mounts using screws or magnets.
Related links:
If you want to learn more, please visit our website BLUE DIAMOND.
Overhead light fixtures with hanging chains. Plugs into standard wall outlets.
We offer 365 nm and 395 nm LED lights for fluorescence and curing applications.
We offer 270 nm UV-C LED lights for germicidal applications.
LED PCBs, panels and other form factors for a variety of industrial and scientific applications.
Bright LED emitters mounted on a flexible circuitboard. Can be cut-to-length and installed in a variety of locations.
Dimmers and controllers to adjust LED strip lighting system brightness and color.
Power supply units to convert line voltage to low voltage DC needed for LED strip light systems.
Extruded aluminum channel profiles for mounting LED strip lights.
Solderless connectors, wires and adapters to join and connect LED strip light system components together.
Before energy-efficient lighting became mainstream, choosing a light bulb was quite straightforward. The 40-watt bulb not giving you enough light? Choose a 60-watt and get more light. Simple and easy!LED technology has allowed for a wide range of possibilities in terms of performance and features, and while this might be seen as a step forward in terms of environmental technologies and for industrial or commercial applications, this makes things much more complicated for the average consumer who just wants to purchase a few light bulbs.With all of the color and light terms, it can be overwhelming and frustrating to know what kind of bulb to purchase. We're here today to help explain and distinguish between two of the more challenging terms that are often confused with each other - CCT (correlated color temperature) and CRI (color rendering index).CCT is a number, measured in degrees Kelvin, that helps to describe the relative warmth or coolness of a light source. Most light bulbs will range from K (warm, incandescent color) to K or higher (crisp, white daylight color).For most residential applications, K and K are preferred color temperature options as they both create a nice, warm appearance that creates an inviting and relaxing environment.For retail or commercial applications, K is a popular color option as it provides for a crisper, more energetic shade of white. For industrial or task-oriented applications, K or even K is a preferred color option, as these color temperatures best match natural daylight.The CRI value of a light source describes how accurately a light source illuminates colors of an object. It is scored on a scale with 100 being the best. Most standard bulbs have a CRI value of 80, while high CRI bulbs have a CRI value of 90 or higher.For example, a painting shown under a 70 CRI light source may exhibit colors that don't appear correct, or accurate. When seen under a 95 CRI light source, however, the colors of the painting will likely look accurate and natural.As explained above, CCT and CRI measure two different aspects of color. CCT tells us the color of the light emitted by the light bulb, and is immediately visible to the casual observer by looking directly at the light source.On the other hand, the CRI value does not tell us the color of the light itself. Rather, it tells us about the color appearance of objects under the light source (the light source "renders" the colors of an object, hence the term). You cannot determine a light bulb's CRI value by looking at the light itself. Instead, a light bulb's CRI can only be estimated to the naked eye by looking at the colors of an object illuminated by the light bulb. An illustrative example of this principle in action is when photographers and artists use a "color checker," which uses a palette of standardized colors to estimate the color rendering quality.The only way to measure a light source's CRI value is by using specialized spectral measurement devices. Lighting manufacturers rely on data from these devices to publish and guarantee color rendering related metrics.Although CCT and CRI describe two different aspects of light color, they are nonetheless intimately related in their calculations. As mentioned above, CRI can be thought of as determining a light source's accuracy. In determining "accurate," however, we must first determine what the reference point for this "accuracy" should be. For example, when judging the color appearance of a painting, how do we know what it should look like? In other words, what is the reference standard?When we refer to light accuracy, we must first determine the color temperature of a light source, so that we have a proper reference point. Each color temperature has a " reference standard " which is considered to be the light source that provides the most accurate, or natural lighting. For example, K has a reference standard that is approximately equal to an incandescent light bulb. K on the other hand, has a reference standard that is approximately equal to natural daylight (at noon on a midsummer day at the equator).To continue with the painting example, if we have a light bulb whose color temperature we measure to be K, we would judge the appearance of colors as compared to an incandescent bulb. We would not compare them to how they appear to natural daylight, because the color temperature of K indicates that this is a warm, yellowish light source that does not come close to natural daylight.On the other hand, if we have a light bulb whose color temperature is measured to be K, we would compare the color appearance to its color appearance under natural daylight.The explanation above should have made clear that CRI requires a color temperature value in order to determine what we are comparing color appearance against.CRI is certainly an important metric that helps explain color quality, but it is almost meaningless when used alone without a color temperature value. Given a light bulb's 95 CRI rating, you might be impressed and conclude that it must be very accurate. But accurate when compared to what? Incandescent bulb light color (K), natural sunlight (K) or natural daylight (K)?Think first about the color temperature requirements for your application, and then worry about CRI after. Are you looking to replicate the light of natural daylight? Pick a high color temperature value (K or higher), and then CRI value next. A K light bulb with 95 CRI, even with a high CRI rating, will not come even close to replicating natural daylight due to its color temperature being way off.Now, in your quest to replicate natural daylight, let's say you find a K bulb but with a low CRI. In this case, the color of light emitted by the bulb might look the same as natural daylight (due to the color temperature value), but as soon as the light lands on any surface with color, you will find that the colors do not appear the same as under natural daylight (due to the low CRI value).We hope this article helped to clarify any confusion between CCT and CRI values of a light source. Have you determined the color temperature needs for your application? If not, we recommend making a decision on this first. Once decided, determine if color accuracy is important for you and set appropriate requirements on the CRI value as needed. Waveform Lighting specializes in high CRI LED lighting products , and we're confident you'll find something that fits your high CRI needs.Still not sure how CCT and CRI are related? We have an interactive graphic available here that illustrates the difference between CCT and CRI.
If you are looking for more details, kindly visit CCT Flexible Led Strip.
Previous: How to Choose the Best LED Strip Light Power Supply
Next: 5 Reasons Why Your Business Needs 5mm Ultra Thin Flexible Led Strip？
If you are interested in sending in a Guest Blogger Submission,welcome to write for us!
All Comments ( 0 )