... matching, reduce grain and minimize extreme dark and light patches. 'Luminance adjustment using the despill' at 10-15% is often used. see: Spill and Fringe Suppresion Use the additive keyer to add grain to the BG(if the ref. has correct matching grain), rather than trying to completely lose the grain via degraining or grading If there is overall ...

... how accurate your roto matte is it will not allow you to accurately unpremultiply it. If your subject were against a background with a consistent colour (such as a greenscreen) then there are ways to despill the colour, but if not then you need a different approach. This technique helps to re-introduce the original colour of your foreground object into ...

... result straight from the keyer that I’m happy with. We now want to add 2 Copy nodes and copy our finished alpha to our original plate as well as the denoised version and finally premult both. Notice the difference between the 2 approaches. Copying the alpha back requires some additional manual work to despill and refine the edges. ...