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-   -   Green Screen Paint? (https://www.dvinfo.net/forum/open-dv-discussion/103679-green-screen-paint.html)

Luca Furgiuele September 16th, 2007 01:32 PM

Green Screen Paint?
 
Just curious about this.
But i want to paint one of my walls green for some green screanin'

just curious if anyones tried this before and what shade of green should i be looking at.
i plan on lighting the wall with work lights like this:
http://www.lonestardigital.com/acces...dio_Lights.jpg

i can get 1500 watts worth of these lights for $50! so as far as i'm concerned it doesn't seem like a bad investment.

Daniel Ross September 16th, 2007 01:52 PM

The lights work out ok. Not as good as pro lights, but certainly not terrible.

Just buy as bright green as possible. Take in a sample if you want, and have them match it. No need to go with the expensive "official chroma" paint. It's all about the lightng, really.

Bill Davis September 16th, 2007 03:19 PM

Well, yes, it's about the lighting to a large extent, but not completely.

One thing you need to make sure of is that your paint is absolutely FLAT.

Not semi-gloss - or (shudder) gloss in any way shape or form.

Bright spots where the key wall reflects the incident light in ANY way are almost guaranteed to give you problems in keying.

Good luck

Jonathan Jones September 16th, 2007 03:45 PM

I have used Home Depot utility lights on sets a few times, and for an extreme budget, they work great in a pinch, however I have not used them for primary lighting at all, always relying instead on a variety of other film and video lighting kits instead.

My experience with utility lights leads me to believe that a big challenge you might experience will be 'even lighting', as these thing might be prone to hot spots which will make your keying a real challgenge, especially as you plan to use these lights fairly close to your illuminated surface.

If you are able to effectively and SAFELY diffuse these lights, you might get a smoother, more even lit surface. I have read a few threads somewhere in these forums about applying a 'sandblast' paint to the glass pane in front of these lights, but I haven't tried that and would be concerned about the amount of heat buildup or flammability of the painted surface given that these things get really really hot.

I'd be curious to know whether or not anyone else has had success with this method and any details about how it was achieved.

-Jon

Luca Furgiuele September 16th, 2007 05:38 PM

i only intend to use the work lights to light the actual green screen itself not the object that i'll film. i'll probably rent lights to light up the character or object

Jonathan Jones September 16th, 2007 06:01 PM

Quote:

Originally Posted by Luca Furgiuele (Post 745260)
i only intend to use the work lights to light the actual green screen itself not the object that i'll film. i'll probably rent lights to light up the character or object

That's my point.

In order to get a good effective key, your green screen or keyed surface should be evenly lit with no glaring hot spots or shadows. You will want your chrominance and luminance values to be as consistent as possible for a good solid but narrow keying range.

-Jon

Benjamin Hill September 16th, 2007 07:06 PM

I agree with all of these answers. In my experience there is a range of greens that will work, but having a very evenly lit and consistent backdrop is really the key. no pun intended

Mark Sasahara September 17th, 2007 03:55 AM

Rosco makes two different green screen paints, Video Paint and DigiComp Paint. A gallon covers about 300 Sq ft. DigiComp is more expensive, but it's part of a system of matching green paint, tape and fabric. This way everything is the same color, exactly. In theory at least, but I've never used the DigiComp, just the regular video paint. Works great.


Be sure that your lighting is even. You can alway garbage matte around the subject if your stage is too small.

Be prepared to add light to various areas, as the actors move, etc, there will be shadows, green spill, etc.

If possible have someone on set, pulling keys, so you can see how everything is looking and view on a large monitor. That way you can spot any trouble.

Benjamin Hill September 17th, 2007 06:02 PM

I took a scrap of Savage chroma key paper to the paint store and had them match it and do several gallons of flat at $10 each. Matched about as well as I could hope for.

Luca Furgiuele September 17th, 2007 06:15 PM

you couldn't tell me what shade that was could you>?

Greg Boston September 17th, 2007 10:29 PM

Quote:

Originally Posted by Jonathan Jones (Post 745206)
I have used Home Depot utility lights on sets a few times, and for an extre I have read a few threads somewhere in these forums about applying a 'sandblast' paint to the glass pane in front of these lights, but I haven't tried that and would be concerned about the amount of heat buildup or flammability of the painted surface given that these things get really really hot.

FYI Jonathan, sandblasting or beadblasting is not painting. It etches the surface of the glass to make it slightly opaque. It's more of an etching process. No paint involved.

Its main use is for cleaning residue from surfaces, but I've masked off coffee cups and beadblasted custom initials on them.

-gb-

Benjamin Hill September 17th, 2007 11:23 PM

Quote:

Originally Posted by Luca Furgiuele (Post 745804)
you couldn't tell me what shade that was could you>?

I don't know what it is called. It looks like Hulk Green to me. There are a bunch of numbers on the lid but I don't know what they mean. Like I said, I matched it from a scrap of Savage chroma key seamless paper.

I think you could use any pure saturated green and if it is flat paint and the wall is very evenly lit it should work.


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