Halation is a characteristic of celluloid film when a bright light bounces back a few times exposing the film a second time only affecting the red layer (and a bit of the green layer) of the film resulting in a reddish/orange glow. The Halation tint may be different based on white balance adjustments / color grading.
An anti-halation layer usually is a coating on the back of the film base, though it is sometimes incorporated between the light-sensitive emulsion and the base. Its purpose is preventing any light from being reflected back through the emulsion from the rear surface of the base, or from anything behind the film. This prevents a halo-like effect (halation). Even with an anti halation-layer there might be a Halo effect because the layer is not 100% black.
Halation Compound Node
Recreation of Halation in DaVinci Resolve
Here is the Halation Node Tree. Packed in ONE “Compound Node” to keep the Node tree tidy and clean.
1. Add a CST Node: In “Color Space Transform” set Output Gamma to “Linear”. 2. Add a Layer Mixer Node. Set Composite Mode to “Add”. 3. Add a Curves Node: Shape the Curve like in the picture. 4. Add a Node for Blur & Gain: Blur the red channel more than the green channel. Play with the values. You can also tint the glow more towards orange using Gain. 5. Add another CST Node. Set Input Gamma to “Linear”.
“Input Color Space” and “Input Gamma” should match your camera. The curve should look like in the picture. Put the “Halation Compound Node” at the first position of your node tree! Click this link to download the PowerGrade. It is free.