Studio 21.1.1
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FUSION & COMPOSITING

How to remove a green screen with Delta Keyer

DaVinci Resolve Studio 21.1 · Original practical guide

A key separates the subject from a colored background. Clean lighting and a sharp source matter; no keyer setting can fully recover a subject hidden by spill or compression damage.

Before you begin

Use a short test clip and open Fusion. Keep MediaOut connected to the final result.

ACTUAL RESOLVE INTERFACEView full size ↗
DeltaKeyer Inspector: background-color sampling control
DeltaKeyer Inspector: background-color sampling control Reference example from the DaVinci Resolve 21.1 manual, page 1717. Software screenshot © Blackmagic Design. The demonstration media and selected settings may differ from your project.

Step by step

  1. In Fusion, place a DeltaKeyer after the green-screen source and merge its result over the replacement background.
  2. Use the keyer’s background-color picker to sample a representative green area near the subject, avoiding shadows and clothing.
  3. Inspect the alpha or matte view. Refine background removal and foreground solidity while preserving hair and transparent details.
  4. Control green spill and inspect the composite over different backgrounds. Review motion and frame edges before adding final color integration.

Check your result

The background is removed, the foreground stays solid, and fine edges do not chatter in motion.

If it doesn’t work as expected

Aggressive matte cleanup can erase hair and soften clothing detail. Use a garbage mask for irrelevant outer areas rather than forcing one threshold to solve everything.

BUILD THE UNDERLYING SKILL

Fusion: think in nodes

Go deeper with the course’s explanations, exercises, and knowledge checks.

Open module 09 →
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Technical reference: DaVinci Resolve 21.1 Reference Manual, Blackmagic Design, September 2026. Screenshot page numbers refer to that manual. Independently written guidance; specific controls may vary by platform and build. Authorship & image credits.