Question / Help Chroma Key Settings for Use with PowerPoint

[Wildhoney]

I've been tinkering around for days with the chroma key settings to use for a PowerPoint presentation (with white background) and I just can't get it right. By the time I get the green out of my hair the edges around my sweater start to blur. When I remove the blur around the sweater the edge around my hair start to blur and get greenish.

Are any of you using white backgrounds and is there a magic setting to keep the edges sharp?

Would love to see your chroma key settings. Thanks for sharing!

 

[Suslik V]

White color is not good for chroma keying (generally, white hasn't chroma).

 

[Wildhoney]

Thank you, I didn't know that. I can try to create a whitewashed background on the PowerPoint. Still, are there ideal settings that people are using that you wouldn't mind sharing with me?

 

[Simes]

The ideal setting for chroma key is to use it with a green (or blue) screen. White backgrounds will never give you a good result with chroma key because white contains no chroma (colour) information.

 

[Wildhoney]

Sorry, I wasn't being clear. I do use a green screen. But I then use a PowerPoint presentation with me in the bottom right hand corner. The PPT has a white background.

 

[Simes]

Oh, then you're looking to reduce the amount of green spill on your back.

Is there room behind you for a bias light? i.e a light, out of sight of the camera, which is aimed at your back. Two lights at the sides should also work. That will help a great deal (and is why people being interviewed in front of green screens are often backlit slightly as well as lit normally from the front).

If there isn't room, is it possible to make room? The further away from you the screen is, the less of a problem green spill will be. Lighting the screen and the subject (you) separately can also help with this, I believe.

 

[Wildhoney]

I am about 3 feet away from the screen and the screens are lit up with 2 studio lights. The light is directed at the green screen behind me, not me. I've found a thread here where someone talked about upping the settings and this seems to have taken care of the green spill. However, it crashed my laptop the first time around. So too tough on my CPU. The challenge is that most people seem to use OBS for gaming related things. I use it for business presentations so I find the instructions tough to follow because I have a moving background (mostly). :-)

Thank you for your help. Appreciated!

 

[Suslik V]

Oh, try to increase Similarity and decrease Smoothness only then for fine tune use Spill Reduction of the filter.
Post log-file, please.

 

[Wildhoney]

Thanks, Suslik. I tried that but I can't get the little fuzz hair around my ears to stop vibrating. I have my hair pulled back tight now with lots of hair spray - and that resolve the issue around the hair. Was hoping others could share their settings so I could try them out.

 

[Simes]

Hair always a difficult thing to chroma key, even in post-production where you don't need to do it live.