Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 223)

HDR PQ Settings
PQ in HDR PQ refers to the gamma curve of the input signal for displaying HDR images.
HDR PQ settings enable the camera to produce HDR images conforming to the PQ
specification defined in ITU-R BT.2100 and SMPTE ST.2084 (with actual display depending
on monitor performance).
Shots are captured as HEIF or RAW images.
* HDR stands for High Dynamic Range.
* PQ stands for Perceptual Quantization.
1.
Select [ : HDR PQ settings].
2.
Select [HDR shooting ].
Select [ Enable ].
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