Holding Alt (Option on macOS) while dragging an Edit slider shows
Lightroom's temporary previews: highlight clipping for Exposure,
Highlights and Whites, shadow clipping for Shadows and Blacks, greyscale
for Sharpening Amount, the detail band for Radius / Detail and the
sharpening mask for Masking. They are render overlays (pipeline
visualize), drawn the same way after the CPU and GPU renderers; the
sharpening views read each renderer's own detail planes. Settings and
normal output are unchanged.
Fixes#937
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
