Lighting
Colour Temperature (Kelvin)
Definition
Colour temperature, strictly correlated colour temperature (CCT), describes the colour of a white light source in kelvins: low values appear warm and orange, high values cool and blue. Typical values are 2700 to 3200 K for tungsten, 4000 K for neutral white LEDs and 5600 K for daylight and HMI sources. Consistency between sources matters more than the absolute value. A room lit uniformly at 3500 K looks natural, whereas 3200 K tungsten mixed with 5600 K LEDs looks wrong on camera and tires the eye.
In the field
Mixed sources are matched with correction gels, CTO on the cooler sources to warm them or CTB on tungsten to bring it towards daylight. The usual practice is to gel whichever type of source is in the minority, because it needs fewer gels.
Related lessons
Sources
- CIE, International Lighting Vocabulary (e-ILV), terme 17-23-068 : définition de la température de couleur proximale · cie.co.at
- Wikipédia (pointeur secondaire), Color temperature : valeurs usuelles (lampes de studio 3200 K, lampes « blanc chaud » 2700 K) · en.wikipedia.org
- PremiumBeat, Understanding set lighting and color temperature : 3200 K pour le tungstène, 5600 K pour le HMI et la lumière du jour · premiumbeat.com
- Feit Electric, Light color temperature guide : 2700 K pour l'incandescence (blanc chaud), 4000 K pour le blanc neutre · feit.com
- Wikipédia (pointeur secondaire), Color gel : filtres CTO et CTB · en.wikipedia.org