The COLOR Workflow - 3D Postproduction: Stereoscopic Workflows and Techniques - page 182

6.7.4 Color Grading
So you i xed everything on your 3D shots and you now are with your colorist
in the grading suite. Congrats!! Now, make sure the colorist understands
3D and you are using a system that handles grading in 3D. Really. Double
check online and with other colleagues about the system. Bring a test to the
colorist to see how he or she handles it before bringing the whole project.
If everything is good, proceed. If anything makes you feel uncomfortable,
look for an alternative.
Now, let's start grading! Overall color grades, no matter how advanced, can
happen at the same time in both eyes (as long as you deliver matched image
pairs). However it is tricky when we get into “power window” land. Color
selections and such can be done without fear, but power windows have to
take depth into account. If you have a character moving from the back of
your 3D scene to the front and you want to bring up the face a bit, that
window will have to follow the convergence of your character or you will be
introducing an artifact that will produce mismatched depth information. If
you are going to select the sky in all the top of your image, you are i ne, as
long as you do it from side to side of the image. Since you are not creating
any difference between the eyes. You just have to mind objects that have a
different horizontal position between the eyes. One trick to ensure you are
placing the masks at the right depth is to do a hard mask i rst and follow
the object/character all through the shot. Correct the color. If it feels at the
right depth, then you can smooth it and everything will be good in the
graded version.