Greenscreen? at DVinfo.net

Stephen Eastwood · February 6th, 2008, 05:22 PM

Looking to set up a small, 8x10 greenscreen for some shot in a small room, say 15x18' would a standard greenscreen backdrop like a muslin like this one http://www.bhphotovideo.com/c/produc...ackground.html be good or is there better without going to an extreme of expensive backgrounds, and would you think two softboxes at the screen and two rims at the actor would be best, should I use a minus green gel on the rims or 1/2 magenta? to counter any green spill?

Would it be helpful at all to use minus green on the mains and rims and WB for that with no filters on the background so the green becomes even more green in relation?

Mains would likely be a soft broad light from two lightbanks of about 4x6 foot size.

Lloyd Claycomb · February 6th, 2008, 07:24 PM

Although not specific to your question, there's a lot of good info on this thread I started. I had/have similar questions: http://www.dvinfo.net/conf/showthread.php?t=113884

Lloyd Claycomb · February 6th, 2008, 07:38 PM

Although not specific to your question, there's a lot of good info on this thread I started. I had/have similar questions: http://www.dvinfo.net/conf/showthread.php?t=113884

Seth Bloombaum · February 6th, 2008, 10:28 PM

Quote:

Originally Posted by Stephen Eastwood

...Would it be helpful at all to use minus green on the mains and rims and WB for that with no filters on the background so the green becomes even more green in relation?...

Minus green on a rim light or back light can help with green spill off the screen. I'm guessing your camera may not white to a magenta source, but what is really at stake here is that you get a foreground subject with none of the screen color and a nice screen of just one color. Perfectly green is not the issue, it is moreso that it reflects as close as possible to a single wavelength.

So, I'd suggest that you keep white light on your fill and key and have nice color rendition and skintones on your subject.

The screen material is fine for most use, and keys are generally easier to cut if there are no visible shadows from wrinkles in the fabric. Many times this is acheived by stretching it between stands, or on a frame, etc.

Steve Oakley · February 6th, 2008, 11:10 PM

virtually all modern keyers handle spill suppression very well. its not as much a problem as you think. just keep people 5+ feet away and everything should be good. I try to keep them 10ft away for waist up shots.

Richard Andrewski · February 7th, 2008, 03:07 AM

Always white balance to the subject lighting but the rim lighting should not be part of the white balance. Turn off the screen and rim lighting and just white balance to the foreground subject lighting.

The idea behind using a magenta (minus green) gel for rim lighting (and a amber for blue screen) is that you pick the color opposite of the screen color to counteract it. As someone else pointed out though, with today's modern screen compositing software, most of the spill suppression takes care of any spill pretty well as long as the separation between subject and screen is good enough to keep it to a minimum.

February 6th, 2008, 05:22 PM	#1
Stephen Eastwood Major Player Join Date: Jun 2007 Location: Great Neck, NY Posts: 291	Greenscreen? Looking to set up a small, 8x10 greenscreen for some shot in a small room, say 15x18' would a standard greenscreen backdrop like a muslin like this one http://www.bhphotovideo.com/c/produc...ackground.html be good or is there better without going to an extreme of expensive backgrounds, and would you think two softboxes at the screen and two rims at the actor would be best, should I use a minus green gel on the rims or 1/2 magenta? to counter any green spill? Would it be helpful at all to use minus green on the mains and rims and WB for that with no filters on the background so the green becomes even more green in relation? Mains would likely be a soft broad light from two lightbanks of about 4x6 foot size. __________________ Stephen Eastwood http://www.StephenEastwood.com

February 7th, 2008, 03:07 AM	#6
Richard Andrewski Major Player Join Date: Jun 2006 Location: Shenzhen, China Posts: 781	Always white balance to the subject lighting but the rim lighting should not be part of the white balance. Turn off the screen and rim lighting and just white balance to the foreground subject lighting. The idea behind using a magenta (minus green) gel for rim lighting (and a amber for blue screen) is that you pick the color opposite of the screen color to counteract it. As someone else pointed out though, with today's modern screen compositing software, most of the spill suppression takes care of any spill pretty well as long as the separation between subject and screen is good enough to keep it to a minimum. __________________ Richard Andrewski - Cool Lights USA - RED #114 http://www.coollights.biz

February 6th, 2008, 07:24 PM	#2
Lloyd Claycomb Major Player Join Date: Jan 2008 Location: Phoenix Posts: 208	Although not specific to your question, there's a lot of good info on this thread I started. I had/have similar questions: http://www.dvinfo.net/conf/showthread.php?t=113884

February 6th, 2008, 07:38 PM	#3
Lloyd Claycomb Major Player Join Date: Jan 2008 Location: Phoenix Posts: 208	Although not specific to your question, there's a lot of good info on this thread I started. I had/have similar questions: http://www.dvinfo.net/conf/showthread.php?t=113884

February 6th, 2008, 11:10 PM	#5
Steve Oakley Trustee Join Date: Apr 2006 Location: United States Posts: 1,158	virtually all modern keyers handle spill suppression very well. its not as much a problem as you think. just keep people 5+ feet away and everything should be good. I try to keep them 10ft away for waist up shots.