What is the TLCI value of a lighting fixture？
Where TLCI values need to be considered?
For a long time, CRI(Color Rendering Index) has been used to judge the capacity of a light source to reduce real colors. CRI is defined for the human eye and is a measurement method of color recognition for a light source compared to standard light sources.
Because of the high efficiency and energy saving feature of LED light source (lamp), It has been widely used in the lighting environment of film and television. Due to the special lighting principle and the specialist of LED light source spectrum. Usually, High CRI index light sources, in the film and TELEVISION shooting, will also be due to the spectrum components and the camera's photosensitive chip color characteristics do not match, showing the color deviation of picture (color distortion).
Therefore, a new measurement standard is needed, which can not only reflect the perception degree of light source color by human eyes, but also reflect the receiving degree of light color and color reduction degree of camera. In November 2011 Mr Alan Roberts, an optical expert of the BBC(British Broadcasting Corporation), in collaboration with the European Broadcasting Union (EBU), put forward together the Television Lighting Consistency Index (TLCI), which is called TLCI-2012.
TLCI is the result of using spectral radiation from a light source spectral energy distribution for measurement and calculation. Through data analysis by software , it is expressed in values from 0 to 100。
Five levels of TLCI
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.
Although at present is mainly a number of film and TELEVISION shooting or broadcast sites come up with clear requirements. However, with the widespread application of smart phones, people will have increasingly strong requirements for shooting scenes, and many places will come up with the demand for TLCI, Stadiums, gyms, night spot, amusement centers and so on will successively come up with such requirements.
It can be seen that TLCI not only puts forward new requirements for indoor lamps and lamps, but also for high-power outdoor lighting lamps in public places. At present, more and more engineering companies have come up with requirements in this respect, especially for large sports venues.