Version 4.1 of the well-known EBU Tech 3320 specification, that defines which monitors used for in professional TV production can be called Grade 1A, 1B, 2 or 3.
Version 4.1 includes several modifications following from tests performed in 2018 (also see EBU Tech Report 047). The changes include (among others): clarification of reference white for HLG and PQ, explicit requirements for several Grade 3 parameters, update of the text on legacy ITU-R BT.709 monitor presets, transfer function characterestic text update, and reference to the new 'Grade 1 HDR colours' defined in EBU Tech 3325s1.
Version 4.0 added High Dynamic Range (HDR) and Wide Colour Gamut (WCG) for both UHD and HD monitors. The HLG and PQ HDR Systems described in ITU-R BT.2100 are included.
To give Members clear guidance the Grade 1 Monitor specification has been split into 1A and 1B. This reflects the current capabilities of monitors to display HDR and WCG images. There are now four monitor grades: 1A, 1B, 2 and 3.
A change log is available here.
The following translations of this document are available. Please note the translations may not be based on the latest version; see the year mentioned in brackets. These translations are courtesy of the translaters and hosted by the EBU 'as is'. The official and definitive version is the EBU English version.
Russian version of EBU Tech 3320  - Special thanks to EBU Member RTR.
If you have any question on EBU Tech 3320, then please contact us. We gather responses to common questions in the list below. If you have other feedback and/or want to contribute to the drafting of future versions of this or other video publications, then please join EBU Video Systems.
Can consumer televisions meet EBU Tech 3320?
They are unlikely to do so.
In general there is a large difference between professional grade monitors ("measurement devices") and Consumer Electronics (CE) devices. In practice CE Televisions may be close to EBU Grade 3 monitors in terms of display characteristics, but they typically differ from professional monitors in terms of interfaces and robustness.
Interface capabilities are evolving. For now the EBU requires HD-SDI interfaces as a minimum (see section 1.5.22). Users are advised to carefully check the capabilities of any other interfaces that may be provided (e.g. HDMI), as implementations may not support all desired formats.
See sections 1.1, 1.2 and 1.3 for more details.
What test pattern is meant with in section 2.3.4?
In section 2.3.4 "Contrast Ratio" a reference is made to "EBU box pattern". This test pattern is defined in EBU Tech 3325, which is currently undergoing amendments to include HDR specific information.
Why is pixel explicitly defined in version 4.0?
There were concerns raised over how the resolution was affected by using WRGB technology. E.g. when adding the W sub-pixel, the resolution may not be 2160x3840 anymore.
Are WRGB panels allowed for Grade 1A/1B monitors?
The text in 2.3.11 seems to hint they may only be appropriate for Grade 2 monitors, but actually this part of the spec is NOT prohibiting the use of WRGB for Grade 1A/1B monitors. Considering a group of RGB or RGBW display elements to be a single 'pixel', in terms of resolution WRGB can meet Grade 1A/1B requirements.
However, the colour volume may be different between RGB and WRGB for the same peak luminance (depending on the relative contribution of the W and RGB sub-pixel elements). For example, a WRGB display may be designed so that 0-500 cd/m2 is reproduced by RGB and 500-1000 cd/m2 by W. The colour volume of this display is less than that of a display with 1000 cd/m2 by RGB only. In general Vrgb >= Vwrgb. So the WRGB panel may fail the specification for full-brightness RGB primary measurements.