High TLCI LED Lighting

What is TLCI？

Considering television lighting must have a minimum quality standard in order to satisfy the audience, the international exchange of programs and the archive, TLCI (The Television Lighting Consistency Index ) was developed by the EBU (European Broadcasting Union) Technical Committee in November 2012 in order to give technical aid to broadcasters who intend to assess new lighting equipment or to re-assess the colorimetric quality of lighting in their television production environment.
Knowing its performance limitations in advance can help in the choice of luminaire, identifying the potential extra cost of color correction in post-production as against the cost saving in power consumption of high-efficiency luminaires. Rather than assess the performance of a luminaire directly, as is done in the Color Rendering Index, the TLCI mimics a complete television camera and display, using only those specific features of cameras and displays which affect color performance. The TLCI is realized in practice using software rather than real television hardware. The only hardware that is required is a spectroradiometer to measure the spectral power distribution of the test luminaire, and a computer on which to run the software analysis program to perform the calculations. This mathematical calculation implemented software is the “TLCI-2012” which is specified in EBU Tech 3355 and available from the EBU as ‘TLCI-2012.zip’.

Five levels of TLCI

The Television Lighting Consistency Index averages 24 colors from the Macbeth ColorChecker chart: Dark Skin, Light Skin, Blue Sky, Foliage, Blue Flower, Bluish Green, Orange, Purplish Blue, Moderate Red, Purple, Yellow Green, Orange Yellow, Blue, Green, Red, Yellow, Magenta, Cyan, White, Neutral 8, Neutral 6.5, Neutral 5, Neutral 3.5, Black.
The maximum value is 100, with 100 being the best

The TLCI values are more spread out into 5 levels

The significance of the TLCI numbering is nearly the same as CRI, but with important differences. As for the CRI, where a score of greater than 90 is widely regarded as the minimum for television use, the TLCI values are more spread out into 5 levels:

• 85~100     Errors are so small that a colorist would not consider correcting them.
• 75~85       A colorist would probably want to correct the color performance, but could easily get an acceptable result.
• 50~75       A colorist would certainly want to correct the errors, and could probably achieve an acceptable result, but it would take significant time to get there.
• 25~50       The color rendering is poor, and a good colorist would be needed to improve it, but the results would not be to broadcast standard.
• 0~25         The color rendering is bad, and a colorist would struggle for a long time to improve it, and even then the results may not be acceptable for broadcast.

TLCI levels with a score greater than 90 indicate a light source widely regarded for television use, that will limit post-production time and labor costs. Therefore, high TLCI lighting is recommended for television programs.

TLCI sample colors in television display

The Macbeth ColorChecker colour-set is often regarded as not being ideally suited to use in television, because one colour (18, cyan) actually falls outside the colour gamut of television when lit by Illuminant D65, and another (16, yellow) lies very near the gamut boundary. However, neither of these apparent problems affects the appropriateness of the colour-set for use in the TLCI-2012. The TLCI takes a measurement of the spectral power distribution of a luminaire, using a spectroradiometer. It then analyses the performance of the luminaire in the context of television.

High TLCI vs high CRI

The TLCI metric (Television Lighting Consistency Index) was developed as an alternative to address the shortcomings of the commonly used CRI when used with photography equipment. Because the way cameras interpret light is slightly different to how humans perceive it, the TLCI attempts to provide a more accurate prediction of color fidelity of a light source for broadcast use.CRI tells us about how a light source renders colors based on human perception. CRI, however, does not necessarily paint a complete picture about how the light source might render colors on camera or on film. Thus, a light source with a high CRI is not necessarily a light source fit for use in film and photography. To this end, the TLCI (Television Lighting Consistency Index) was developed. The metric is analogous to CRI in that a high TLCI metric tells us that a light source will render colors well in a film or photography context.

What does Yujileds^® offer for high TLCI LED lighting?

1. With the advanced LED technologies, Yujileds^® focuses on supplying specific solutions of high TLCI LEDs for photographers and lighting equipment manufacturers for television use.
2. Yujileds^® has released its full spectrum series of violet chip powered LEDs (VTC) with TLCI up to 99.
3. With the deep understanding of television studio application, Yujileds^® develops its high TLCI LED with a technical balance of spectrum between biological vision and electronic induction.
4. With sufficient manufacturing experience, Yujileds^® is capable to provide convincing reference to guarantee the accurate and consistent performance on product quality, stability and color rendition.
5. With wide CCT options, Yujileds^® offers all feasible colors of high TLCI LED for television lighting including customization demand.
6. Starting with LED package, Yujileds^® provides integrated solutions for customized flexible strip or metal core PCB of high TLCI LED products.