Keyer / Chroma issues

Hello all,

I have a concern using the Keyer in FCPX. When I drag the Keyer onto the clip of the speaker (who is standing in front of a green screen), the image immediately loses some saturation and goes a slight reddish colour making the blues look more purple (as seen in his suit jacket). It is causing colour correction nightmares for me. Does anyone know what is causing this as I've scoured through YouTube and haven't see anyone else encountering this issue after the drag and drop of the Keyer Effect. 'Before' and 'After' screen Grabs are attached. Many thanks to all!!

James

When you add the built in Keyer to a clip, it makes a "judgment" about how much green (or blue) "color cast" needs to be corrected and it automatically sets the Spill Level to a value (which tends to be different for every clip its added to). When I added Keyer to your sample image, the value of the Spill Level we 73%.  That amount will add more magenta to the subject. Dial that back down to about 50% or a little lower. [Spill Level above 50 tints magenta - below 50 tints back towards green.]

If you want to add a little saturation back in, I would recommend using the Hue/Saturation effect
for the easiest way to deal with it.

Here is my result:



I used a Spill Level of about 35% and an added saturation of 0.48. For completeness, I also adjusted the Matte Tools > Levels > Bias to 0.1 (to get rid of extraneous background "noise")... but that's all I did with this sample. [PS - if the jacket looks a little more green, that's because I have "issues" with certain shades of green -- i.e., I'm partially color blind in a limited range of hues in the green spectrum which appear absolutely neutral (gray) to me. You'll have to make your own judgment of which spill level value to use.]

HTH