keylight

Hi all.

* INtermediate result should be RGB (source) + alpha (SCREEN MATTE) to use it later in your three. Is that correct? when I do this, my screen matte that i previously made and INtermediate result alpha look very different !
Can anyone can Tell me why?

* Color replacement. Is there a way to correct the blue screen luma. Like to key out a white bright element and semi transparent element like milk from a dark blue screen. The color replacement play with tint- but what about the brightness?

*DESPILL
as keylight do the despill automatically with the screen color. I want to know if the despill is made just by comparing the pixel and the screen color OR
do also take in account the alpha generated to do the automatic despill.
So do the despill on the the SEMI transparent area.....

thanks if u have any clue.