The production of color depends on the interaction of the light source, the object, and the observer. Light sources typically emit light in the 400 nm to 700 nm wavelength band, which covers the spectrum visible to the human eye, including red, orange, yellow, green, cyan, blue, violet, and other colors. When this light hits an object, the pigments or other substances in the object selectively absorb and reflect different wavelengths of light. The combination of wavelengths of the light reflected by an object determines its color. Therefore, the nature of the light source has an important impact on the colors we see. For example, CWF and TL84 fluorescent light sources, although both are fluorescent light sources, differences in their spectral composition and luminescence properties affect the color performance observed under these light sources. What's the difference between the two?
OneWhat are CWF and TL84 light sources?
CWF (Cool White Fluorescence) light source is a standard fluorescent light source that is commonly used in shopping malls and offices in the United States. It has a color temperature of 4150K and complies with the CIE (International Commission on Illumination) standard illuminator F2. The CWF light source has a color rendering index (CRI) of about 62 and is characterized by emitting a large amount of green light and a small amount of red light, so it is often used by many American brands for color matching.
The TL84 light source is a narrow-band fluorescent light source, which belongs to the trichromatic fluorescent lamp. This light source is widely used in shops and office environments in Europe and the Pacific Rim. It has a color temperature of approximately 4000K and complies with the CIE standard illuminator F11. The TL84 light source has a color rendering index of about 85 and is characterized by the release of a large amount of green light. Customers in Europe and Japan often specify TL84 light sources for color matching because their higher color rendering index provides better color reproduction.
IIThe difference between CWF light and TL84 light source
Color temperature
There is a slight difference in color temperature between the CWF (cool white fluorescence) light source and the TL84 light source. According to the requirements of the light source in the SpectralLight QC light box, the color temperature standard for the CWF light source is 4150 200K, while the color temperature standard for the TL84 light source is 4000 200K. Although the color temperatures of the two light sources are similar, they still exhibit slightly different light color characteristics. Color temperature refers to the temperature at which the light color emitted by a light source matches the light color emitted by an ideal blackbody at the same temperature, usually measured in Kelvin (k). Small differences in color temperature can cause slight changes in light color, but this difference is usually not noticeable to the human eye, especially when the color temperature difference is small.
Color rendering index CRI
The Color Rendering Index (CRI) is a quantitative measure of a light source's ability to reproduce the color of an object. The CWF (Cool White Fluorescence) light source has a color rendering index of approximately 62, which means that its performance in color reproduction is moderate and may not accurately reproduce all colors. In contrast, the TL84 light source has a color rendering index of about 85, indicating that it has better color reproduction capabilities and can represent colors more accurately.
As can be seen from the spectral power distribution diagram in the annex, there is a significant difference in the spectral distribution between the CWF light source and the TL84 light source. For example, a CWF light source has a higher peak in the green region and a lower luminous intensity in the red region. In contrast, the TL84 light source also shows a higher peak in the green region, but the luminous intensity in the red region is significantly higher than that of the CWF light source. These differences in the spectral distribution result in different color reproduction of the two light sources, which may affect our perception and judgment of the color of the object. Therefore, it is important to consider the color rendering index and spectral power distribution of the light source when selecting a light source for color matching and evaluation.
Scope of application
CWF (Cool White Fluorescent) light sources are widely used in commercial environments in the United States, so customers in the United States may specifically specify CWF light sources to evaluate color. For example, well-known retail and branding companies such as Apple, PVH, Ann Taylor, Home Depot, Sears, and Walmart may use these light sources to ensure color consistency in their products (although Walmart has already begun to transition to LED lighting).
In Europe, TL84 light sources are widely specified for color evaluation as a standard choice for commercial fluorescent lamps. European customers such as Marks & Spencer, Decathlon, Zara, Adidas and other brands often choose TL84 light sources in their color management processes. This reflects regional differences in standards and preferences for light source selection, and it is critical for brands operating globally to understand these differences.
X-Rite SPLQC light boxes offer a variety of light source options, including seven different light sources including CWF and TL84, as well as optional LED light sources. This versatility makes it a useful tool to support color evaluation at multiple stages of design, calibration, pre-production, production, as well as quality assurance and outgoing quality inspection. By using this light box, color issues can be identified and corrected, thereby reducing waste and rework caused by color errors, which may help reduce the time to market for products and hopefully improve the overall quality of the product.
3. Year-end preferential activities
Year-end special offers, don't miss the opportunity! X-Rite limited-time discount on select products. There is also a "trade-in" promotion to help you save procurement costs, and other brands and models of the same category can also participate. For more information or to participate in the event, please contact X-Rite for details.
Fourth, about X-Rite
X-Rite Pantone is headquartered in Michigan, USA, and was founded in 1958. As the world's leading color trends, science, and technology company, X-Rite Pantone provides services and solutions to help brands, manufacturers, and merchants manage color from design to final product. If you need more information, please follow the official WeChat*** X-Rite Pantone.