Guest January 31, 2017 Share January 31, 2017 Why are they used interchangeably? I have seen it written as BT.709 and sometimes as REC.709. What does BT and REC stand for? Link to comment Share on other sites
Andy Minuth January 31, 2017 Share January 31, 2017 The full name is 'Recommendation ITU-R BT.709 - Parameter values for the HDTV standards for production and international programme exchange' Recommendation: The ITU is responsible for defining worldwide standards. They are then published as recommendations. ITU-R: International Telecommunication Union Radiocommunication Sector BT: This recommendation is part of the 'Broadcasting service (television)' series. 709: The number of this paper. Rec.709, BT.709, etc. are different abbreviations for the same thing. You can download the paper for free here: http://www.itu.int/rec/R-REC-BT.709-6-201506-I/en Fun fact: As far as I know, a transfer curve for displays (e.g. for mastering or color grading) was not defined in ITU-R BT.709. Everyone was using Sony CRTs back then, which made them the de facto standard. In ITU-R BT.1886 the eotf for displays was finally defined. 4 Link to comment Share on other sites
