Creating an even Green Screen

Having an uneven green screen may lead to a lot of extra work down the line of a compositing process. Follow these steps to ensure that you start your composite workflow with the cleanest green screen possible.

[Denoise] the footage

• Sample area for denoise

Use [Keylight] to create a solid core matte. Don't worry about the background.

• Sample Screen Color

• Toggle with Screen Balance, Clip White, and Screen Despot Black

[Invert] the footage

From [Denoise], use [IBKColour] to create a solid black object sitting inside the original object

• Change screen type to green

• Reduce blur size (start with 5)

• Analyze the RGB channels and adjust dark and light to create a solid black patch (0.04)

• erode and patch black till solid black object sits the original

IBKColour

Copy [keylight] and [invert] from above and [divide] the two [invert]

• The goal is to divide the background to get a solid white

• Since black= 0 the black object in front is not affected

[Shuffle] the alpha to RGB

RGB

Create negative luminance of the original

• Create [Constant] from green sample

• Have the [Constant] [minus] [IBKColour]

[Multiply] with the [Shuffle] to generate a correction plate and [plus] to the original

Final result

Full node graph

https://www.linkedin.com/learning/vfx-keying-master-course/screen-correction-workflow?u=2208146