User Manual

Introduction to Compositing
Using the Alpha Output
While DaVinci Resolve can use the alpha channel of imported media for compositing, the Alpha
Output in the Node Editor is an optional output that you can turn on to create clip transparency
using operations inside DaVinci Resolve to create composites against other clips on lower
video tracks. There are many ways of using the Alpha Output, but this section will focus on
three examples.
Using a Qualifier Key to
Create Transparency
In this first example, the Alpha Output will be used to composite a green screen clip with a
background plate.
A green screen clip, ready for compositing
In preparation for this composite, the background plate is on track V1 of the Timeline, and the
green screen clip has been superimposed on track V2.
A superimposed green screen clip on track V2 of the Timeline,
above a background plate on track V1, ready for compositing.
To create a chroma-key composite in the Color page:
1 Right-click anywhere within the gray area of the Node Editor and choose Add Alpha
Output to add the Alpha Output at the right of the node graph.
An Alpha Output appears underneath the Node Tree output at the right of the
Node Editor.
The image Node Tree output
with Alpha Output below
Chapter – 127 Channel Splitting and Image Compositing 2886