chrome key quality

[milena]

Hello everybody,

My company makes a daily news show using virtual studios and chrome key. I am not satisfied with the look of the chrome, the edges are jagged and there is a green glow around the hosts.
We are using component video input. Each person has front and back light, and the greenscreen is lit evenly.. almost.
Any suggestions how could I improve this?

[Randy Rouse]

Just a few thoughts:

Magenta gels on the backlights

Avoid getting talent to close to green background

Even lighting on green screen

VT5 is going to have improved support for live keying/virtual set

[tfrank]

In addition to Randy's suggestions... if you are recording your video and not doing a "live" chroma key, you'll get better results by not using a compressed video source such as an AVI. We get excellent results by recording an RTV.

[UnCommonGrafx]

Gotta concur on using rtvs.

However, I suspect he means the live version. You REALLY REALLY have to have everything balanced out to not get chattering and bad edges.

Paul told me about some flourescent light fixtures that might work for you but I've had a catastrophic crash that lost that info. Here's hoping Paul or someone at NewTek who knows about this stuff will chime in and give some direction on where to find that info. Otherwise, I'll ask tomorrow.

The bigger your glow around your talent the closer they are to the backdrop. Use a bigger backdrop so they can be farther away. Ten feet plus would be my initial suggestion.

[Paul Lara]

Paul told me about some flourescent light fixtures that might work for you but I've had a catastrophic crash that lost that info. Here's hoping Paul or someone at NewTek who knows about this stuff will chime in and give some direction on where to find that info.

Robert,
The fixtures we used to shoot with were from Brightline (http://www.brightlines.com/). The single-fixture flourescent was about $600 and the double-lamp unit was ~ $800. They put off flicker-free light, and never get hot.

Best of all for chroma-keying, the light is so very soft from our key and fill fixures, it wasn't necessary to use any lights dedicated to lighitng the green wall; we just let the spill beyond the talent light the wall behind them.

BTW, our talent was about 10' in front of the wall.

[Bobt]

>BTW, our talent was about 10' in front of the wall.

This is a BIG one when doing a Key to avoid the green edges.
You also need a camera with good resolution. (uncompressed 700 lines)

This is when you notice a consumer or DV compressed camera can destory
even the best setup because it can not resolve the edges of your subject
without serious bleed/blend.

bob

[NVentive]

Also remember -- a properly painted wall will usually work better than a hanging screen.
Other light sources --

http://www.coollights.biz/
http://www.skaeser.com/servlet/Categories?category=COOL+FLO

good luck -- S