Advanced Despill Operations When Chroma Keying In Resolve Fusion

Chroma Keying Part 5: Mastering Advanced Despill operations and Color Corrections based on Spill Maps.

In this Insight, we continue with our Chroma Keying in Fusion series. This time we’re tackling the important topic of ‘spill’ – when the colored light of our chroma key wraps around the foreground and taints the natural colors of the foreground. If we don’t tackle the spill, our composite becomes less convincing and can pull the audience out of story.

You will step up our efforts from earlier in this series to learn advanced techniques for managing spill, particularly in challenging scenarios with reflective surfaces or complex edges. We will remove the spill while maintaining luminance and leverage a spill map for advanced color correction or adaptive despill to naturally blend the keyed image with the new background.

Understanding the nature of ‘spill’

Spill is caused by two different effects when shooting green/blue screen footage (or any other colored background).

First, we can have green light from the screen that falls onto the actor and leads to a color cast.

Sometimes, skin tones turn slightly towards green or yellow, or bright clothing shows green spill. We may simply want to remove this spill. However, depending on the new background, we may decide to preserve the luminance from the spill or even replace the spill light with a different-colored light to emulate the new environment.

Second, we have colored artifacts where pixels contain mixed information from the foreground and background.