HDR & colour
EOTF / PQ (SMPTE ST 2084)
The brightness curve of HDR: PQ for HDR10/Dolby Vision, HLG for broadcast, gamma for SDR.
What is it?
An EOTF (electro-optical transfer function) defines how a code value becomes light on the screen. SDR uses a gamma curve (~2.4) relative to the display's white. HDR10 and Dolby Vision use PQ (Perceptual Quantizer, SMPTE ST 2084), an absolute curve up to 10,000 nits. HLG is a hybrid curve for broadcast.
Why it matters with the HDfury Vertex²
The EOTF field in the infoframe is what actually flips a display into HDR mode. The HDfury Vertex² lets you set it explicitly — 'SMPTE ST 2084' to force HDR mode, 'HLG' to force HLG mode, or 'SDR luminance range' to keep a display in SDR while feeding it HDR content (useful for projectors with a custom gamma curve).
How to use it on the Vertex²
Web server → HDR/DV → EOTF dropdown in the custom HDR metadata generator → Create IF → Send HDR.
Related terms
- HDR10 — The baseline HDR format: 10-bit, PQ curve, BT.2020 with static metadata.
- HLG (Hybrid Log-Gamma) — The broadcast HDR format from BBC/NHK used by TV channels and YouTube; no metadata.
- HDR metadata: MaxCLL, MaxFALL, mastering display — The numbers inside an HDR10 signal that tell a display how bright the content is.