"Crushed Blacks” is when black levels are underexposed causing an overall loss of detail in the shadows/ darker portions of the image.
Crushed Blacks impact Content quality of the asset. Customer experience is negatively affected by any loss of detail, as creatively intended visuals or story points may be missed.
Substantial portions of the image have minimal detail due to black levels being crushed.
How to Prevent:
Be aware of camera aperture settings to ensure proper exposure.
Ensure base black levels and max luminance levels do not exceed allowable thresholds.
Find a balance between lows and highs during color grading to maintain as much detail as possible across the image.
Confirm if creative intent or best possible. Otherwise review/ address possible conformance issue or Full/Legal Range conversion issue.