What is the TM-30-18 Color Reproduction Guide and Report

2024/04led strip light source

The ANSI/IES TM-30 standard is an internationally recognized set of guidelines for characterizing the color rendition of virtually any light source, such as LEDs.

In 2018, IES released an update to TM-30: the TM-30-18 standard, which extends the original TM-30-15 standard. TM-30-18 provides a more comprehensive evaluation of the color quality of new light sources, particularly for solid-state lighting (SSL). TM-30-18 is now widely accepted as the solid-state lighting color reproduction standard and reporting format. The newer TM-30-20 standard provides detailed guidance on calculations used for objective characterization of light sources but retains the TM-30-18 reporting format.

TM-30-18 replaces the V-shaped Fidelity Index chart in the TM-30-15 report and introduces the Hue-Angle Bins chart, as shown below. Note that the circular image in the lower left corner shows 16 segments separated by dashed lines. Rather than just displaying the data points for all 99 individual TM-30 samples around the perimeter of the circle, the samples are grouped into "bins" and their average fidelity scores are reported on a color vector plot as Rf (marked in the upper left corner).

Luminus LED (30-95-AC40, 3000K) TM-30-18 Report

TM-30 hue angle boxplots are represented as histograms, with the local color fidelity (Rf, hj) score for each bin shown above each column (lower right corner). Additional histograms have been added:

local hue shift - the percentage difference in hue (color) between the test source and the reference source for each bin
Local chroma shift – The percentage difference in chroma (saturation) between the test source and the reference source for each bin.
As shown in this example report, high color rendering index Luminus LEDs have excellent color rendering. For comparison, the image below is an example of good (incandescent, right) and bad (fluorescent, left) results in the full TM-30-18 report format for a light source near 3000K. These examples are created using the built-in Calculator database example set.

The image below shows the appearance of 99 CES samples compared to 99 reference sources tested. The differences are evident for multiple samples illuminated by CIE F4 spectra. The incandescent light source (right) is defined as 100 CRI and therefore has excellent color fidelity.

Complete TM-30-18 report format and color difference comparison of CES samples. The "bad" example on the right is CIE F4, a standardized representation of a 2900K fluorescent light source. The "good" example on the left is a 60W incandescent lamp (2800K) chosen as a representative sample by the CIE.


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