Light Color Temperature

Human are attracted easily by outstanding objects. The visual appearance of objects is given by the way in which they reflect and transmit light. The color of objects is determined by the parts of the spectrum of (incident white) light that are reflected or transmitted without being absorbed. Additional appearance attributes are based on the directional distribution of reflected (BRDF) or transmitted light
(BTDF) described by attributes like glossy, shiny versus dull, matte, clear, turbid, distinct, etc.
Research about which lighting is most beneficial in demanding has proven that the use of LED lighting with a CCT of 4000 K and high CRI is relatively more activating.

The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of a comparable hue to that of the light source.
The color of light is designed in kelvin (K). The lower the kelvin, the ” warmer ” the light – from yellow to orange to red. The higher the Kelvin, the ” cooler ” (bluish-looking) the light.


TM-30-15 is a new and improved IES method for characterizing the color rendering ability of white light sources. While CRI and extended CRI utilize 8 and 15 color samples, respectively, they do not necessarily represent the actual colors that we would encounter in the real world. The new fidelity index (Rf) developed under TM-30-15, on the other hand, utilizes 99 color samples in its calculation, providing a much more statistically representative and reliable metric in describing a light source’s ability to faithfully render colors. In line with CRI, the best possible
score for Rf under the TM-30-15 rubric is 100.


In addition to an improved color fidelity metric, the TM-30-15 method introduces an additional dimension to color quality through the gamut index (Rg). The Rg gamut index provides information about the relative range of colors that can be produced (via reflection) by a white light source. A score close to 100 indicates that, on average, the light source reproduces colors with similar levels of saturation as an incandescent bulb (2700K) or daylight (5600K/6500K). For LEDs of decent color quality, Rg can typically range between 80 and 120, with higher scores representing higher overall levels of saturation.