ITU-R BT.1886 recommendation specifies the reference electro-optical transfer function (EOTF) that the displays used in HDTV programme production should follow.
It was not needed when CRT displays were the norm, because all CRT displays had a very similar non-linear response (Gamma). This response needs to be created within a flat panel display such as LCD or OLED.
The reference EOTF is specified as a simple equation, with exponent function (power law), based on measured characteristics of the Cathode Ray Tube (CRT).
See Gamma
