The amount a particular color correction filter alters a light source.
From TLS,Inc. tools - Filter Fax :
From TLS,Inc. tools - Filter Fax :
CTO color correction filters have a positive mired shift; CTB s have a negative shift. The higher the number, the greater the shift.Mired shift value is a constant value. It thereby provides a method for accurately predicting the effect of a color correction filter, regardless of the starting Kelvin temperature of the original source.