Edge and light selection
The mask considers highlight energy and local contrast so lamps, windows and hard daylight edges can respond more strongly than broad white surfaces.
Emulsion color around hard light
Controlled film halation around real light
Halation appears when intense light passes through film emulsion, reflects from the support and exposes the color layers from behind. The visible result is not a red glow over every bright pixel: it is a localized orange-to-red halo near sufficiently bright, high-contrast boundaries.
The response
What this tool changes
Layered color
The inner boundary leans orange while the wider, lower-energy halo becomes redder, reflecting the different penetration of the emulsion layers.
Source protection
The halo is built around the source without increasing the source itself into clipping. Skin, skies and graphic overlays are restrained to prevent indiscriminate red contours.
DaVinci Resolve workflow
A practical way to use it
- Start with a correctly transformed and balanced image.
- Enable halation and raise the amount while watching a real bright boundary at normal viewing size.
- Adjust the available selection and spread controls only far enough to connect the halo to the source.
- Check daylight skies, faces, white clothing and titles before approving the shot.
Restraint matters
What to avoid
A halo around every bright object reads as a digital edge effect. Broad clouds and white walls usually lack the compact source energy that creates strong halation. Also avoid using halation to warm the entire image; print color and shadow color are better tools for global bias.