TLCI — Television Lighting Consistency Index
Definition
The Television Lighting Consistency Index (TLCI), published by the EBU as EBU Tech 3355, rates how a light source renders colour on a television camera, whereas the CRI models the human eye. The score, from 0 to 100, is computed through a model camera and display, and a score of 85 to 100 means that the colour errors are small enough for a colourist not to consider correcting them. A fixture can score well on CRI and poorly on TLCI, because a camera's colour filters do not respond in the same way as the cones of the eye.
In the field
For camera work, the TLCI value is requested in addition to the CRI. A fixture with a CRI of 90 but a TLCI of 70 can still produce unnatural skin tones on broadcast cameras, because the camera perceives colour differently from the eye.
Sources
- EBU Tech 3355, Method for the assessment of the colorimetric properties of luminaires (TLCI-2012) : modèle de caméra et d'écran, échelle 0 à 100 · tech.ebu.ch
- Bridgelux, TLCI-2012: a new color quality metric for television lighting : de 85 à 100, écarts trop faibles pour qu'un étalonneur les corrige · bridgelux.com