A New Era in Color Rendition Measurement: TM-30-15

The way we perceive color is closely tied to the quality of the light that illuminates it, but we need some tools to test that quality. For centuries, we have relied on the traditional Color Rendering Index (CRI) to assess the color rendering capabilities of light sources. However, these traditional metrics often fail to accurately capture the nuances of human perception of color. To address this color rendition measurement, the Illuminating Engineering Society (IES) introduced a groundbreaking standard: TM-30-15.

What is TM-30-15 Color Rendition Measurement?

TM-30-15 is a color rendition measurement method developed by IES. It is designed to provide a more comprehensive and detailed assessment of color quality than CRI. CRI uses eight color samples to calculate a general average of color accuracy.

TM-30-15, on the other hand, uses 99 color samples to provide a broader and more detailed assessment of a light source’s color rendering. TM-30-15 generates two main indices – Rf (Color Fidelity Index) and Rg (Gamut Index), which provide a more precise and realistic understanding of color rendering.

By using TM-30-15, lighting professionals can more accurately assess color rendering, making it easier to select the right light source for the desired visual effect. In applications where color quality is critical, such as retail, healthcare, and architectural lighting, the move to this advanced method is essential.

Why is Color Rendition Important?

Color rendering is a critical factor in the visual environment, affecting everything from mood and productivity to safety and satisfaction. In retail spaces, accurate color rendering helps display products in a more attractive and realistic way. When you choose the CRI, pls read Why CRI is Important? 80 CRI vs. 90 CRI vs. 95 CRI

In healthcare, precise color rendering can help medical professionals diagnose symptoms. Additionally, well-rendered color can enhance architectural and interior design projects by faithfully presenting the textures, colors, and aesthetics that designers intended.

The TM-30-15’s color rendition measurement comprehensive approach to color rendering enables lighting professionals to fine-tune their lighting designs, achieve better color accuracy, and enhance the visual experience in a variety of applications. This focus on quality and fidelity addresses specific needs that CRI alone cannot fully meet.

How TM-30-15 Color Rendition Measurement?

The TM-30-15 method assesses color rendition through two main indices—Rf (Fidelity Index) and Rg (Gamut Index)—and a detailed color vector graphic that visually represents color shift tendencies. Here’s how each component contributes to a thorough color rendition assessment:

• Rf (Color Fidelity Index): Measures the accuracy of color reproduction compared to a reference light source. This index is akin to CRI but calculated using a broader range of color samples (99 compared to CRI’s 8). An Rf score close to 100 suggests high color fidelity, meaning colors appear natural and true under the light source.
• Rg (Color Gamut Index): Assesses the saturation or vividness of colors rendered by the light source. An Rg value of 100 means no change in color saturation, while values above 100 indicate increased saturation, and values below 100 indicate desaturation.
• Color Vector Graphic: TM-30-15 also includes a color vector graphic that shows color shifts across various hues, providing lighting designers with a visual tool to understand how a light source will affect color appearance.

This multi-faceted approach makes TM-30-15 a more powerful tool for understanding color rendition than any single metric could provide.

How Does TM-30-15 Differ from Traditional CRIs?

The traditional CRI measures color accuracy based on only eight color samples, which limits its scope and precision, especially when applied to modern lighting technology. TM-30-15, by contrast, measures color fidelity with a much larger set of 99 color samples, covering a broader range of hues, shades, and saturation levels. Here are some key differences:

• Sampling Variety: TM-30-15’s 99 color samples provide a much more comprehensive basis for evaluating color accuracy, allowing it to capture subtle color discrepancies that CRI may overlook.
• Dual Indices (Rf and Rg): CRI primarily focuses on color fidelity alone, while TM-30-15 evaluates both fidelity (Rf) and gamut (Rg), providing insights into color accuracy as well as vibrancy.
• Visual Tool for Color Shift: TM-30-15’s color vector graphic visually represents how hues are altered under a light source, giving designers a practical, user-friendly way to predict and control color shifts in real-world applications.

By addressing the limitations of CRI, TM-30-15 has become an invaluable tool for industries requiring precise and detailed color rendition.

Understanding the Rf and Rg Indices

In TM-30-15, the Rf and Rg indices work together to offer a comprehensive picture of color rendition.

• Rf (Color Fidelity Index): Similar to CRI, Rf evaluates the closeness of colors to a reference source. It ranges from 0 to 100, with higher values indicating higher color accuracy. However, unlike CRI, Rf covers a wider spectrum of colors, making it more representative of actual color fidelity in varied applications.
• Rg (Gamut Index): Rg measures the light source’s ability to enhance or reduce color saturation. An Rg score of 100 suggests that the source neither oversaturates nor desaturates colors, while scores above or below indicate respective increases or decreases in color vibrancy.

Together, Rf and Rg allow lighting designers to understand both color accuracy and saturation, tailoring lighting environments for specific needs, whether that’s true-to-life color accuracy or enhanced vibrancy.

Applications and Benefits of TM-30-15 in Lighting Design

The improved color rendering evaluation of TM-30-15 provides numerous benefits for numerous lighting applications. We can cite the following industries where color rendering evaluation is important.

• Retail: Accurate color rendering helps display products in their true colors. For example, fruits and meats. This can improve customer satisfaction and increase the likelihood of purchase.
• Healthcare: In medical settings, accurate color rendering is essential for accurate diagnosis of symptoms. This is especially true in dermatology, surgery, and patient assessment.
• Art and Museums: Art exhibitions and museum displays benefit from lighting that faithfully renders the colors the artist intended, ensuring an authentic viewing experience for visitors.
• Architecture and Interior Design: For architects and designers. Accurate color rendering helps achieve the desired aesthetic and ambience by displaying materials and finishes in their true colors.

TM-30-15’s dual-index approach allows lighting professionals to make informed decisions about color fidelity and saturation, resulting in lighting designs that enhance environments both functionally and aesthetically.

Conclusion

TM-30-15 represents a significant advancement in the measurement of color rendition, addressing the limitations of CRI with a more comprehensive and accurate approach. By utilizing a larger color sample set and introducing the Rf and Rg indices, TM-30-15 enables lighting professionals to evaluate color fidelity and saturation more precisely.