Secondary colur correction mask not working! Help!

Question

I am currently working on Premier Pro CS6 editing a music video. I have edited my footage, fixed the tonality and I am now onto color grading it. I took the saturation down to take out the colour and applied RGB curves to add blue into the shadows and then another fast colour corrector to give the video a blue/black depressed feel.
Going through my footage I wanted to take out certain colours that were too vibrant still. So I thought to make a mask. This is where my problem starts. I open up the three way colour corrector and the RGB curves and go down to secondary color correction and go to mask. When I try to take a sample from the dropper Premier doesn’t pick up the colour from where I want but selects it in other areas of the footage but never on the area I want! I have tried this on my mac book pro and the same is happening. When I have tried it on rushes it seems to work. I don’t understand why it doesn’t work when I have colour graded my footage?! I have tried many different discussions but nothing is pointing me forward. If anyone has any idea of why this is happening and how to solve my problem I would be so thankful!

Answer 1

Hi ACD,
After Effects and Photoshop CS6 take .Looks via the LUT engine. That indeed allows for using primaries with low mid high differentiation and should yield really good results.
Secondaries can be expressed in a LUT as well, but I would typically not recommend using them when you want to integrate .Looks with your After Effects workflow. Here's why:
- a LUT is never as precise as you'd want it to be for something as complex as secondary color grading - a LUT is always based on interpolation (as opposed to applying the effect in SpeedGrade - there it's all native, no interpolation at all)
- For a good key you would typically use the denoise and the blur function in the secondaries. Both (by nature) don't translate at all into a LUT, so you'd have to give up using these 2 important tools
- For a lot of work you'd want the LUT to be accompanied by a mask. That's something that also can't be described in a LUT.
Think of the LUT support for .Looks you created in SpeedGrade more as a really helpful tool for matching your comps to an overall look you design, not necessarily as the tool to apply a final grade.
Hope this is helpful.
Pat