View Full Version : Green Screen
07-07-2007, 10:44 AM
Hey forgive me if this has been explained already but i'm new to green screen. I have just purchased one but am not sure on how to use it. I know i have to record the subject in front of the green screen , but how do i put the pictures or moving objects in the green screen while the person stands in front of it?
07-07-2007, 10:53 AM
scotch tape - just kidding :)
The purpose of the green screen is to provide a large consistent color to key out later in post. In your NLE you should have an option for chromakey or maybe even a greenscreen key. This will mask out anything of that particular color leaving your subject floating. Then you can layer anything underneath the video and it shows up behind your talent. Thats the cheap and easy explanation from someone who has done it once.
There's alot of green screen info on these boards covering how to work it in post as well as how to properly light and shoot one.
07-07-2007, 11:21 AM
wut editing system u using
07-07-2007, 02:00 PM
In final cut
Make sure u have ONE color, behind your subject, its alright if there is a lightr area, or a dark area, just harder to key. The more lighting, the niceer key you get. Make it chromatic (One color)
in final cut, put the fotoage wit the green screen material, and put it on the second track (or 3rd, or anything AFTER tyhe first track, this is where your gunna put the source footage of whatever you want to go behind your subject)
then adda chroma key, or a greenscreen key, or a color key, or whatever your NLE offers you. If you have trouble keying, you might wanna boost and bump up the greens, so the NLE will pick up the greens better, dont make them to high because then your subject will get green. A way to do this is to add a level, and change the level meter to green (or blue if your using a blue screen)
once you have keyed out the footage, make sure to feather the edges, so its not sharp and jagged. You can add a spill supressor (green or blue) for this, so give the edges more color, other than green
once you have all your work keyed, apply a video, an animation, a video or whatever you want to the track BENEATH the green screen footage.
NOTE: BEFORE you key out the color, you should adf the background first, becauser if you key out the footage, and then add it in, the color might be off, and it might not look as good. If you add the background image first, then you no how much to key, how much to do this, and your set!
07-07-2007, 03:48 PM
Hey dont pull the key in final cut use after effects or some other compositing program or buy a plug in that is specifically designed for greenscreen extraction. FCP's chromakey filter is terrible!
07-07-2007, 04:20 PM
From my own makeshift green screening I've discovered that simple studio lighting works best. Two lights (in my case worklights) with umbrellas/diffusers pointed at the subject on angles should eliminate any shadows.
Thats the best picture of a setup we used to film a friends project. The green screen is some wrapping paper (way off perfect chroma-key green but it worked for the purpose)...
If you're waiting for the screen you ordered to ship, don't be hesitant to just try it out on a small scale with some wrapping paper/construction paper.
I hear that 3rd party companies (not the main FCP/Avid/Premiere/Whatever) have better software for keying out backgrounds. I'm still back in the past working with premiere 6... Cant say the keying is beautiful either, but it's a good learning start:
07-07-2007, 11:29 PM
Thanks alot everyone :)
07-07-2007, 11:30 PM
Sony Vegas 6
07-08-2007, 06:45 AM
I bought a green fabric screen from Amvona.com. The 10 x 12 foot one that I got sells for about $60.... they have much larger ones for equally inexpensive prices. They're nicely made, with large, brass grommets for hanging them, etc.
Then I build my own "strip lights" to light the fabric evenly. Starting with $8 chrome, 5 light strip lights fron Lowe's (intended for bathroom lighting)... and some aluminum channel to hold foam core panels, laminated with "chrome" finish poster board from the art supply store...... I rigged up some very effective lights, that use household 75 watt bulbs. Not terribly elegant, but it works great. I use DV Matte Blast (from DVGarage.com) which is a plug-in for Apple Motion. It previews in real time... and is very easy to learn to use.
If you'd like to see pictures of my setup... go to http://www.soaringstuff.com/greenscreen/