Spot clipped highlights and shadows in a photo

The job

Clipped pixels have no detail left — pure white or pure black. Knowing that clipping exists is easy; knowing whether it hit the sky or the subject's face is what this answers.

Zone mode first

Drop the photo and pick the zone palette: shadow clipping paints blue, highlight clipping red — the same convention as camera exposure aids. Toggle between zones and a luminance palette (viridis/thermal) to see the tonal distribution.

• Small red patches on light sources are usually fine; a red face is not.
• Blue in a night sky is expected; blue across clothing texture means lost detail.

Then fix

This is a diagnostic, not a repair — nothing is recovered. Use it to decide whether the shot needs re-editing (pull highlights down in your editor) or re-shooting, then export the check image if you want a marked-up reference.