User guide

KeylightThe Foundry
TUTORIAL
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Tutorial 3: Extreme Blue Spill
Tutorial 3: Extreme
Blue Spill
This is a really interesting clip from the film Merlin. The results with Keylight
are certainly not perfect, indeed it is unlikely that you will ever end up with
a truly realistic looking shot. However, there are some interesting things to
observe. You will learn how to:
• Reduce the blue spill using Screen Balance and Despill Bias.
• Improve the foreground opacity using Alpha Bias.
1. Load the MerlinBlueFG.tif (Figure 70) and MerlinBlueBG.tif clips and apply
Keylight.
Figure 70. A tricky blue screen.
2. Pick the Screen Colour.
Figure 71. Serious blue spill.
Pick some pure blue pixels away from the hair.
3. Increase the Screen Strength from 100 to 105. This will clean up a little
of the background. Look at the Status to see the difference.