ColorBox In-Line Color and HDR/SDR Transform v1.0 37 www.aja.com
BBC HLG LUT Name, Number
Description
SDR Scene UpMap > HLG Strict, #6-2a For use with SDR cameras that implement a strict BT.709 OETF BT.709 signals are up-
mapped (inverse tone-mapped) to BT.2100 HLG using a scene-light conversion. The
“look” of the original BT.709 content is changed, so that the native look of BT.2100
HLG cameras is achieved. While the ITU-R BT.2408 signal levels are taken into
account, a small boost is applied to the SDR highlights so that there is a closer match
to natively produced HDR content. A 100% SDR signal is up-mapped to 79% HLG.
105% SDR signals (EBU R.103 “preferred range” signals) are up-mapped to 83% HLG.
NOTE: Unlike BT.2100 HLG, SDR cameras that implement a strict BT.709 OETF tend
to crush detail in the shadows of a scene. Such detail will become more visible after
applying this conversion. It is often better to adjust the SDR camera’s native OETF to
approximate a square root (which provides a better match to HLG) and then use LUT
6-1.
SDR Display > HLG, #3c
For use with SDR Graphics. BT.709 signals are directly-mapped into BT.2100 HLG at
the BT.2408 signal levels using a display-light conversion. The “look” of the original
BT.709 content is therefore preserved on conversion. A 100% SDR signal is mapped
to 75% HLG (“HDR Reference White”).
SDR Display UpMap > HLG, #5c
For use with SDR Graded Content. BT.709 signals are up-mapped (inverse tone-
mapped) to BT.2100 HLG using a display-light conversion. This LUT is designed to
complement LUTs 8 and 9 (BT.2100 HLG to BT.709 down-mapping) so that losses
associated with ‘round-tripping’ (i.e. SDR-to-HDR-to-SDR conversion) are minimized.
While the ITU-R BT.2408 signal levels are taken into account, a modest boost is
applied to the SDR highlights so that there is a closer match to natively-produced
HDR content. The LUT does, however, attempt to preserve the artistic intent of the
original BT.709 content. 100% SDR signal is up-mapped to 82% HLG.
SDR BT.2020 Disp > HLG, #17c
For use with SDR Graded Content. BT.2020 signals are directly-mapped into BT.2100
HLG at the BT.2408 signal levels using a display-light conversion. The “look” of the
original BT.2020 content is therefore preserved on conversion. A 100% SDR signal is
mapped to 75% HLG (“HDR Reference White”).
SDR BT.2020 Disp UpMap > HLG, #18c For use with SDR BT.2020 Graded Content. BT.2020 signals are up-mapped (inverse
tone-mapped) to BT.2100 HLG using a display-light conversion. While the ITU-R
BT.2408 signal levels are taken into account, a modest boost is applied to the SDR
highlights so that there is a closer match to natively produced HDR content. The
LUT does, however, attempt to preserve the artistic intent of the original BT.2020
content. 100% SDR signal is up-mapped to 82% HLG.
PQ 1000 Nits Display > HLG, #1e
For use with Graded Content. BT.2100 PQ signals are converted to BT.2100 HLG in the
1000 cd/m2 “bridge” condition, so that 1000 cd/m2 PQ maps to 100% HLG. Please
refer to ITU-R report BT.2390 Section 7.2 (“Conversion concepts using a reference
condition at 1000 cd/ m2”). With the Type III LUTs, PQ signals above 1000 cd/m2 are
mapped into the HLG “superwhite” signal range up to 109% signal, equivalent to
1811 cd/m2 (PQ).
PQ 4000 Nits Display > HLG , #2e
For use with Graded Content. 4000 cd/m2 BT.2100 PQ signals are converted to
BT.2100 HLG by first tone-mapping to the 1000 cd/m2 “bridge” condition, and then
converting to HLG. The tone-mapping is applied to the luminance component so
that hue distortions are avoided
NOTE: that 4000 cd/m2 PQ maps to 100% HLG. For more information, please refer to
ITU-R report BT.2390 Section 7.4 (“Handling PQ signals with greater than 1000 cd/m2
peak-luminance”). With Type III LUTs, PQ signals above 4000 cd/m2 are mapped into
the HLG “super-white” signal range.
S-Log3 100% Scene > HLG, #10a
For use with Sony S-Log3 cameras in non-live workflows. S-Log3 (BT.2020 color)
signals produced using the Sony’s “100%” workflow (i.e. 100% IRE input equals 90%
reflectance) are converted to BT.2100 HLG with ITU-R BT.2408 signal levels. A 100%
IRE input signal (90% reflectance) thus maps to 73% HLG. A scene-light conversion is
used, so that the converted S-Log3 signal is a close subjective-match to the “look” of
BT.2100 HLG cameras.