In a previous post I described a test I performed with After Effects and Blender Nodes. The test image was a green screen shot. I was asked about the green screen setup, so I wrote an article about it on my blog. If interested, you may check out the article here:
Great stuff - it’s groundbreaking research like these that help us all.
Why didn’t you simply use paint for the setup? At a local film studio (Blue Ridge Motion Pictures) I was told that paint is used for most Hollywood motion pictures because it can’t fold over itself like fabric and diffuses the light better. (50-150 dollars)
Why did you pick green? Its a pretty common color when someone refers to chroma key, but doesn’t seem to work as well as white/blue (with me anyway). White is my preference simply because it is a great light deflector and can be diffused VERY easily.
Have any idea why white isn’t as common as blue/green? Worked great for a film I did last summer…
green is the most popular because you’ll find that green is the least likely colour to be found in human skin. So if you’re pulling a colour key then it’s ideal. I think that most compositors would tell you that something that acts as a great light deflector (ie is highly reflective) is not a good choice for a background which will be matted out, as the last thing you want to do is spend time removing reflected light from your subject!
for a lot of studio shots we use chroma rolls which are less permanent than white and do not fold. they’re like portable, massive blinds that work very well. Suggest anyone interested in less painful methods of keying checks them out.
I need my green screen setup to be portable. Painting walls is not an option for me.
As far as choosing green, a simple google search will yield many results explaining why studios choose blue or green for chroma keying.
Thanks for the responses…
FourthOrder: suppose that portability is a good reason to go with fabric.
Dan: I don’t seem to have trouble using white. (Shot a short promo last year) It only reflects at a 90 degree angle as long as the screen is stationed correctly - this provides backlight. I also noticed that white screen reflections look very natural when compared to that of green/blue. Last year I shot half the promo in green and another half in white, I was required to “shrink the mask” when using green while the white came out looking great… I didn’t use a 3 point lighting setup though (Which could have something to do with it) and utilized the white as a light.
I suppose that it is mostly personal preference.
Edit: White screen takes a little more effort to light though.
When choosing a material for your green screen, always think about the lighting. Shiny materials yield bad results, as they reflect light and make replaced areas seem paler. What you have to look for is a matte surface. Matte surfaces will diffuse light; causing even lighting across the entire material, and therefore, a narrower color range. That is, there will be less reflected light; paler outcomes, and less shadows; non-replaced outcomes.
isn’t that supposed to be portable… I know paint is portable, but the people where you’re filming might take exception to you painting one of their walls green or blue or errrr… red? ahem.
Wow… the comments are just awesome. Nikolaus: you are talking about some 90 degree angel thing, can you please provide a picture of the same so newbies like me can get a better idea?
Harrison: I was not aware that shiny material can play a major role in the quality of the video. Thanks anyways for all the tips.
it’s not the quality of the video, it’s the usefulness of the shot. if you have to spend an extra two hours painstaking roto’ing out reflected light, then the shot is less useful than the one you spent an extra £20 on by buying the expensive matte paper… regardless of the temporal, spatial or colour quality of the footage.