Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 184)

Highlight Tone Priority
You can reduce overexposed, clipped highlights.
1.
Select [ : Highlight tone priority].
2.
Set an option.
[ Enable ]: Improves gradation in highlights. The gradation between the
grays and highlights becomes smoother.
[ Enhanced ]: Reduces overexposed highlights even more than
[ Enable ], under some shooting conditions.
Caution
Noise may increase slightly.
The available ISO range starts at ISO 200. Expanded ISO speeds cannot be set.
With [
Enhanced ], results in some scenes may not look as expected.
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