how to read green values during shoot

[Terry Mikkelsen]

“…and a lot of experience with chromakey…”

Tech-T Productions
http://www.technical-t.com

[Mary Waitrovich]

Terry, I think I missed the first part of your answer, can you please repeat?

Mary Waitrovich
Media Plus You, LCC
http://www.mediaplusyou.com

[Jeff Schroeder]

Mary,

I don’t know how you would read the color values ‘live’ during a shoot, other than importing a test shot and taking a frame capture and checking the rgb.

I looked at some of my chroma footage and found a range from 103,190,117 on the bright side to 71,141,83 on the dark side. This was all from one frame on one camera. I don’t recall having too much trouble keying this. I use New Blue’s chroma key instead of the one supplied with Vegas.

One thing I can say is that you want your screen lit as evenly as possible. Mine is cloth that hangs from 9 feet up, curves at the floor and extends about 12 feet from the wall. I use 3 -500 watt halogens with a softener on each. They are about 3 feet above my screen and about 2.5 feet in front of it. My talent is about 6.5 – 8 feet in front of the screen and lit from 2 points. I do not use a hair light or a back light, because of the huge amount of light already behind the talent.

You want to be careful of shadows because they can be hard to work around. I recreate all my shadows from a silhouette of the keyed footage.

I hope my 2-cents worth helps you in some way.

Jeff

http://www.narrowroadmedia.com

[Mary Waitrovich]

Thanks, Jeff. I’m reshooting because the green screen was too hot the first time around and I ended up with a green halo around the hair I couldn’t get rid of in Vegas. I just want to get it more near true green to avoid problems. I use two big cool flo soft boxes on the green screen and that lights it pretty evenly. I’ve had pretty good luck with Vegas’s chromakey, but sometimes I have to resort to Keylight in Aftereffects if the footage is giving me problems.
Thanks for your thoughts.
Mary

Mary Waitrovich
Media Plus You, LCC
http://www.mediaplusyou.com

[Mike Kujbida]

Mary, if your camera has a zebra pattern option, this is what to use for setting exposure.
I light my talent first, get an exposure reading on him/her/them and then use the zebra pattern to set the green screen to the same exposure level.
Ideally, as Jeff said, you want an evenly lit screen and it sounds like you have that covered with the lights you have.
If they’re too bright, either move them further away or invest in some diffusion material specifically designed for TV lights.
Rosco is one company that makes a wide range of it.

[Stephen Mann]

The Vegas chromakey is pretty good, but it doesn’t have good spill control. Try downloading the demo of NewBlueFX Chromakey.

Steve Mann
MannMade Digital Video
http://www.mmdv.com

[Danny Hays]

Vegas has no spill suppression in it’s chromakey pluggin. If the lighting isn’t perfect, Backlight your subject well. some use a magenta backlight as it’s the opposite color from green and can cancel out some spill, Vegas’s isn’t worth using otherwise. Newblue is better and has spill suppression but if you have access to Keylight (After Effects 7 or later) or Ultra Key, those in my opinion are the best keyers around.