The Standard: ITU-R BT.1886 defines only a reference Electro-Optical Transfer Function (EOTF). No white point. No color primaries.
The Claim: Despite this, color scientist Charles Poynton states: “BT.1886 already has primaries, D65, and [an] EOTF,” making it a full “DISPLAY colorspace.”
The definition: As defined by ISO 22028-1, a color space requires three components:
1. RGB Primaries
2. A White Point
3. A Transfer Function
The Verdict: BT.1886 provides only (#3). It contains zero specifications for (#1) primaries or (#2) a white point. These are exclusively defined by ITU-R BT.709.
Therefore, the claim that BT.1886 is a color space is false.
End of story.
Industry Perspective
“The appendix in BT.1886 informatively repeats some info from BT.709 to clarify the transfer function in 709 is a reference OETF for capture and not a reference EOTF for display. The BT.1886 EOTF is also specified for BT.2020 capture and so does not specify a color space, only a reference EOTF. It can also be used with other primary chromaticities.” Jack Holm, President & CTO, Tarkus Imaging
Former Principal Color Scientist at Hewlett-Packard; co-inventor of image-specific color rendering (US Pat. 6,249,315); key contributor to ICC color management and AMPAS ACES. | LinkedIn comment
The Daejeon Chronicles 