Projecting a green screen onto a wall at DVinfo.net

Ian Stark · November 17th, 2008, 02:40 PM

Hmmm . . . not sure about this.

I am shooting a corporate for a client and have travelled to the US to do so. That means I have limited access to equipment. The locations that were described to me over the phone aren't really as I was expecting them to be and won't meet my needs. However, the client has a large conference room with a big screen and data projector. The room can be completely blacked out. What I am wondering is whether it's possible to project a green image onto the screen and use that as a green screen background. The talent will be able to stand away from the ceiling mounted projector so as not to cause shadows and I have 2 x 600W lights and a pair of Lowell Pro 250W focusable lights (and lots of space) to more than adequately light them.

What is it that I am missing here? There must be something that will mean this won't work!

Can anyone make me see sense before I commit to using their conference room? Or better still, tell me that it's a great idea!

Thanks,

Ian . . .

Oren Arieli · November 17th, 2008, 03:21 PM

Interesting idea. Having never tried it, I would only caution that your white balance be correct so that the screen 'reads' green, and the lighting (for the talent) doesn't spill on the screen. The talent's lighting should be of similar color temp to the projector, otherwise you might have color-balance issues.

If you have access to DV Rack on a laptop or some portable vectorscope, you can easily check out the color balance (handheld meter would also be great to have).

Best of luck.

Ian Stark · November 17th, 2008, 03:52 PM

Oren, many thanks. Hadn't considered the colour temp issue. Luckily I do use DV-Rack so I'll look at that tomorrow. Thanks again. Ian . . .

Jim Andrada · November 17th, 2008, 11:14 PM

I think the actual color of the screen isn't particularly important- as long as it isn't too close to the color of something the talent is wearing, their eye color, hair color, threads in the suit jacket or tie color, etc. I've heard of people pulling successful keys with red in addition to the standard green, blue, or whatever.

Evenness of the screen though is important

Maybe a nice Windows "blue screen of death" would suffice.

Dean Sensui · November 18th, 2008, 02:58 AM

Maybe you can rent or borrow a green screen. Let folks here know where you are and, if you're lucky, there will be someone nearby who can get you a good bundle of fabric that you can use for a few days.

Or maybe buy an EEFX.com green screen. It folds up nicely, unwrinkles on its own, lights extremely evenly and gets excellent results.

Ian Stark · November 18th, 2008, 08:27 AM

Jim, BSOD would work!

Dean, good idea. I've already been in touch with the local videographers association who have already been very helpful. To be honest, I'm working to a tight budget and I'm reluctant to spend any more - especially as the pound is weakening against the dollar by the hour! Additionally, I have full greenscreen capability at home so I'd be doubling up on things I already have (but can't easily throw on a plane).

I think I'm going to have a go with the projector (we have now found a room with back projection which should be better still).

Thanks for the suggestions everyone. I'll let you know how successful (or otherwise!) we are.

Ian . . .

Paul Cascio · November 18th, 2008, 08:38 AM

The biggest problemis spill, espcially since a projection screen is deisgned to reflect as much light as possible. Also, viewing angle of the screen is more limited than if you were using a green cloth backdrop.

Finally. lighting your talent without light spilling onto the screen is also a challenge. I've thought of using my 72-inch projection TV as a green screen, but haven't tried it yet. It's picture is also directional.

Ian Stark · November 18th, 2008, 09:10 AM

Good points, Paul, thanks for bringing them up.

We are fortunate in this situation in that a) i am only shooting head and shoulders, b) I can position the talent a good six feet in front of the screen which will help with spill, c) the room is very big so I can be very flexible in where I place my lights and d) I'm shooting head on so no worries about angles.

I'll keep an eye on light reflecting off the screen.

Thanks again.

Ian . . .

Josh Laronge · November 18th, 2008, 09:21 AM

What about buying a roll of paper? I realize you said you don't want to spend anymore. Understandable. But, you can get a roll of green paper for around $40.00. Not much, if it saves your shot and makes your life easier.

Ian Stark · November 18th, 2008, 09:48 AM

Also good advice, Josh, thanks. If it goes horribly wrong I'll probably do just that. We're just setting up to make some tests at the moment so let's see how it goes.

Edward Phillips · November 18th, 2008, 09:54 AM

I may be way off here but projectors always seem "flickery" to me. I really don't know much about projectors but do they work somewhat with a framerate? Meaning, would the projector project out the green color image 24 times a second? That may affect you if you shoot at different frame rates and the greenscreen flickers or is in and out on frames. Kinda like shooting a TV or computer screen. Seems like an old slide projector with a green slide would be more constant than a digital projector.

November 17th, 2008, 02:40 PM	#1
Ian Stark Inner Circle Join Date: Dec 2003 Location: Hampshire, UK Posts: 2,237	Projecting a green screen onto a wall Hmmm . . . not sure about this. I am shooting a corporate for a client and have travelled to the US to do so. That means I have limited access to equipment. The locations that were described to me over the phone aren't really as I was expecting them to be and won't meet my needs. However, the client has a large conference room with a big screen and data projector. The room can be completely blacked out. What I am wondering is whether it's possible to project a green image onto the screen and use that as a green screen background. The talent will be able to stand away from the ceiling mounted projector so as not to cause shadows and I have 2 x 600W lights and a pair of Lowell Pro 250W focusable lights (and lots of space) to more than adequately light them. What is it that I am missing here? There must be something that will mean this won't work! Can anyone make me see sense before I commit to using their conference room? Or better still, tell me that it's a great idea! Thanks, Ian . . . __________________ www.vit-media.com www.classicmachinefilms.co.uk

November 17th, 2008, 03:52 PM	#3
Ian Stark Inner Circle Join Date: Dec 2003 Location: Hampshire, UK Posts: 2,237	Oren, many thanks. Hadn't considered the colour temp issue. Luckily I do use DV-Rack so I'll look at that tomorrow. Thanks again. Ian . . . __________________ www.vit-media.com www.classicmachinefilms.co.uk

November 18th, 2008, 02:58 AM	#5
Dean Sensui Inner Circle Join Date: Oct 2001 Location: Honolulu, HI Posts: 2,054	Maybe you can rent or borrow a green screen. Let folks here know where you are and, if you're lucky, there will be someone nearby who can get you a good bundle of fabric that you can use for a few days. Or maybe buy an EEFX.com green screen. It folds up nicely, unwrinkles on its own, lights extremely evenly and gets excellent results. __________________ Dean Sensui Exec Producer, Hawaii Goes Fishing

November 18th, 2008, 08:27 AM	#6
Ian Stark Inner Circle Join Date: Dec 2003 Location: Hampshire, UK Posts: 2,237	Jim, BSOD would work! Dean, good idea. I've already been in touch with the local videographers association who have already been very helpful. To be honest, I'm working to a tight budget and I'm reluctant to spend any more - especially as the pound is weakening against the dollar by the hour! Additionally, I have full greenscreen capability at home so I'd be doubling up on things I already have (but can't easily throw on a plane). I think I'm going to have a go with the projector (we have now found a room with back projection which should be better still). Thanks for the suggestions everyone. I'll let you know how successful (or otherwise!) we are. Ian . . . __________________ www.vit-media.com www.classicmachinefilms.co.uk

November 18th, 2008, 08:38 AM	#7
Paul Cascio Trustee Join Date: Sep 2004 Location: Bristol, CT (Home of EPSN) Posts: 1,192	The biggest problemis spill, espcially since a projection screen is deisgned to reflect as much light as possible. Also, viewing angle of the screen is more limited than if you were using a green cloth backdrop. Finally. lighting your talent without light spilling onto the screen is also a challenge. I've thought of using my 72-inch projection TV as a green screen, but haven't tried it yet. It's picture is also directional. __________________ Paul Cascio www.pictureframingschool.com

November 17th, 2008, 03:21 PM	#2
Oren Arieli Major Player Join Date: May 2007 Location: San Jose, California Posts: 918	Interesting idea. Having never tried it, I would only caution that your white balance be correct so that the screen 'reads' green, and the lighting (for the talent) doesn't spill on the screen. The talent's lighting should be of similar color temp to the projector, otherwise you might have color-balance issues. If you have access to DV Rack on a laptop or some portable vectorscope, you can easily check out the color balance (handheld meter would also be great to have). Best of luck.

November 17th, 2008, 11:14 PM	#4
Jim Andrada Inner Circle Join Date: Feb 2007 Location: Tucson AZ Posts: 2,211	I think the actual color of the screen isn't particularly important- as long as it isn't too close to the color of something the talent is wearing, their eye color, hair color, threads in the suit jacket or tie color, etc. I've heard of people pulling successful keys with red in addition to the standard green, blue, or whatever. Evenness of the screen though is important Maybe a nice Windows "blue screen of death" would suffice.

November 18th, 2008, 09:10 AM	#8
Ian Stark Inner Circle Join Date: Dec 2003 Location: Hampshire, UK Posts: 2,237	Good points, Paul, thanks for bringing them up. We are fortunate in this situation in that a) i am only shooting head and shoulders, b) I can position the talent a good six feet in front of the screen which will help with spill, c) the room is very big so I can be very flexible in where I place my lights and d) I'm shooting head on so no worries about angles. I'll keep an eye on light reflecting off the screen. Thanks again. Ian . . . __________________ www.vit-media.com www.classicmachinefilms.co.uk

November 18th, 2008, 09:21 AM	#9
Josh Laronge Major Player Join Date: Dec 2006 Location: Jupiter, FL Posts: 241	What about buying a roll of paper? I realize you said you don't want to spend anymore. Understandable. But, you can get a roll of green paper for around $40.00. Not much, if it saves your shot and makes your life easier.

November 18th, 2008, 09:48 AM	#10
Ian Stark Inner Circle Join Date: Dec 2003 Location: Hampshire, UK Posts: 2,237	Also good advice, Josh, thanks. If it goes horribly wrong I'll probably do just that. We're just setting up to make some tests at the moment so let's see how it goes. __________________ www.vit-media.com www.classicmachinefilms.co.uk

November 18th, 2008, 09:54 AM	#11
Edward Phillips Regular Crew Join Date: May 2008 Location: Memphis, TN Posts: 118	I may be way off here but projectors always seem "flickery" to me. I really don't know much about projectors but do they work somewhat with a framerate? Meaning, would the projector project out the green color image 24 times a second? That may affect you if you shoot at different frame rates and the greenscreen flickers or is in and out on frames. Kinda like shooting a TV or computer screen. Seems like an old slide projector with a green slide would be more constant than a digital projector.