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TM30-18 or CRI ¿Which is more important?
The Colour Rending Index (CRI) is a numerical value from 0 - 100, which idicates the
quality of light with respect to the sun. A light source with a CRI of 100, supposedly offers
a chromatic reproduction similar to that of the sun which means that any product exposed
to that light will be seen with its natural colours, as if it were iluminated by sunlight.
In the photo we can observe that the hamburger with a high CRI reflects the real colours
more accurately, the value of R9 (red) being the most important of all.
The CRI with its 15 values (colours) isn’t complete enough to be able to carry out the
best quality testing. This is due to the fact that with only 15 values we could reach a false
assumption. The CRI can’t prevent us from designing a light source with the specific idea
of having a high result with these 15 colours, while the existing colour spectrum is poor in
general (see the photo where we have 2 values with identical CRI and yet both luminous
spectrums are very different).
Therefore the TM-30-18 is a new standard which can tackle this problem. It has been proposed by
leading organizations in USA, the IES (Illuminating Engineering Society) and the DOE (Department
of Energy in USA). The TM-30-18 offers the Colour Fidelity Index (Rf) with the same quality scale
up to 100, but with much higher levels of precision due to its increase in test colours (from 15 to
99 colours).
As the test colours have been substantially increased, it’s practically impossible to have false
readings. Only those light sources which have similarities with daylight or with the standard illuminant
in the full spectrum, will obtain values greater than 90 or 95.
Spectrum, considering 15 values
Spectrum, considering 99 values
Luminous spectrum with sunlight
Luminous spectrum with sunlight
Luminous spectrum with Sevilla ecoled
Our ecoled Full Colour strips, Sevilla model (see page 266), offer a luminous spectrum which
is almost identical to sunlight, therefore achieving an excellent chromatic reproduction. Our
laboratory (in our Barcelona installations) offers the most technologically advanced systems and
with our spectroradiometer, equipped with an integrated sphere, we can carry out corresponding
measurements for TM30-18 in order to guarantee the most rigorous and exact readings for our
clients.
