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Filmmaking Dictionary: Letter R / Rec.2020 (BT.2020)
Definition
Rec.2020, formally ITU-R BT.2020, is an international recommendation for ultra-high-definition television production and programme exchange. It defines image and signal parameters including a wide set of RGB colour primaries. Those primaries describe a larger colour gamut than Rec.709.
In an editing or grading application, a “Rec.2020” setting often identifies colour primaries or an output colour space. Read the rest of the setting: the name alone does not specify every aspect of an HDR master.
Rec.2020 vs Rec.709
Both use a D65 reference white, but their RGB primaries differ. Colours that fit inside the Rec.2020 gamut may lie outside the smaller Rec.709 gamut. Converting between them therefore requires the appropriate colour transform and, where necessary, a decision about handling out-of-gamut colours.
Changing a file’s colour label without transforming its values can change how the image is interpreted. It does not perform a proper conversion. Likewise, expanding Rec.709 material into a larger encoding space does not recreate colours the source never captured.
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Rec.2020 Is Not the Same as HDR
Colour gamut describes a range of chromaticities. Dynamic range concerns the range of light levels represented and reproduced. These are related parts of an imaging system, but they are separate properties.
BT.2100 specifies HDR television systems using PQ or HLG and the same wide-gamut primaries associated with BT.2020. A practical HDR specification must identify the appropriate transfer system and other delivery requirements; “Rec.2020” by itself is incomplete.
Monitoring Limits
A display can accept a Rec.2020 signal without reproducing every colour inside that gamut. Signal compatibility and actual panel gamut are different specifications. The viewing system may map colours into the display’s available range.
This matters when approving saturated lights, graphics or costumes. A convenient monitor may show an acceptable version while concealing clipping or shifts elsewhere in the delivery chain. Use the required reference setup and examine scopes as part of the check.
Preparing Deliverables
- Confirm the required colour primaries and whether the programme is SDR, PQ HDR or HLG HDR.
- Check bit depth, codec, signal levels and metadata against the delivery specification.
- Apply the intended colour-management output transform.
- Create and review any required SDR version rather than assuming it will match automatically.
- Check the exported file on a suitable playback path and identify each master clearly.
For a project with an HDR master and an SDR web version, the SDR conversion may need a separate trim pass to preserve the intended balance of highlights and saturated colours. A single export preset cannot guarantee that creative match.
Related Terms
- Rec.709 (BT.709)
- 10-Bit / 12-Bit / 16-Bit
- 4K Resolution
- Luminance
- Quality Control (QC) in Post-Production
Browse terms beginning with R or return to the filmmaking dictionary.