Lighting
Colour Temperature (Kelvin)
01 — Definition
The perceived colour of a light source, in Kelvin: low values pull towards warm orange, high values towards cool blue. Reference points: tungsten 2700 to 3200 K, neutral white LED 4000 K, daylight/HMI 5600 K. Consistency counts for more than the absolute value — a room lit uniformly at 3500 K looks natural, whereas 3200 K tungsten mixed with 5600 K LEDs rings false to camera and tires the eye.
02 — In the field
Put CTO on the cooler sources to warm them, or CTB on tungsten to take it to daylight. Gel the minority source: it is less work.