Luminance contrast: curves beat a single Contrast +50 slider
Global contrast often crushes fabric texture into black and blows skin highlights into paper white. `luminance-contrast` helps foggy days, dull scans, and photocopy rescans: segmented curves or luminance masks can lift mids while keeping pupil and cloud-gap detail. Strong moves on JPEG reveal block stair-steps along edges. For print, mind highlight dot percentages so speculars do not become empty paper. Batch jobs should bucket exposure instead of one aggressive curve for every file. Forensic, medical, or illustrative evidence should not be dramatized for aesthetics—state processing if the image is public. Archives that need both visible mold and scholarly citation can keep a low-contrast master plus a display punch pass so researchers are not forced to cite an over-stretched derivative. HDR, log, or very wide-dynamic-range masters need a working gray and highlight rolloff before global contrast; otherwise sky and skin get punished by the same S-curve. If viewers will see auto-enhance in apps or browsers, note that the shipped file is the reference, not their on-device preview.
Luminance contrast steps
- On `luminance-contrast`, label whether you are lifting haze or taming blown highlights.
- Zoom into hairlines, weave, and cloud rims for micro-transition.
- Before export, confirm the histogram is not pinned at either end.