How to color correct to a bright white background

[Emily37439336cavu]

Hi there!

Hoping someone can steer me in the right direction. We recently filmed on a white screen so that we can overlap the speaker onto white ppt slides for a lecture. I received the footage in 4k CRM raw files and have to use a LUT to take it from the raw image to the color corrected image. I'm running into the issue where no matter the LUT or color changes I make, I cannot get the image to the natural looking and bright white backgorund. I feel like I'm close, but could anyone help me figure out what I'm missing?

[R Neil Haugen]

That's a very difficult thing to do, actually. As you need to lift the surrounding near-white pixels, without lifting those of the subject. It's really little different from green/blue screen working.

There are two ways to approach it ... the first is easier but works only if your white background/text area and subject will be static.

You use a feathered layer of Lumetri to 'lift' the pixels where it blends with the ppt image ... using a mask.

So you say have your ppt on V1, and the speaker on an upper track. You would put a mask around the speaker, feathered, and then 'below' the mask, Lumetri to lift the whites to 100IRE. Or whatever IRE level your ppt file shows as.

If the speaker waves their arms too much, this won't work.

If that is the case, you need to mask the whole subject pretty close, and track that mask. Adjust as needed. And then key out the background outside the mask.

This is pretty much the same task as green/blue screen working.

[Emily37439336cavu]

Thank you for your time and the ideas!

I ended up starting super basic before I tried more intricate things, seeing as I had to do this to about 20 different presentations and I'm new to video editing. I added the LUT and color corrected intensely to start, took me a few hours. From there, I was able to get the background super close to being bright white or I was able to key out the speaker as if it was a green screen. I tried the mask at one point, but I may need more practice with it down the road.

Appreciate the help! Now I know the skills I need to sharpen in my tool box!