Green or Blue screen?

hey guys,

I've never dealt with green or blue screen before. Does anyone know any links that will teach me step by step on how to do it. I have this scene in which the character is starring at the computer screen. There is green over the computer and i want to put images there. HELP!!!

Green, because blue only has an 11 percent luminance value and gets lost in the noise.

Keying from a compressed video stream (DV, HDV) is a challange compared to uncompressed or lightly compressed. Keying from HDV will qualify you for sainthood.

Mabe Ken Stone?

[www.kenstone.net]

Koz

If you have an area that is already green, in the foreground, such as you described, then this is not a valid use of Keying.

Keying an image out of a background involves the entire image being surrounded by a Green or Blue Screen and using the Keying software to extract that image for reuse.

If the green is in the computer screen and the image is moving around and you want a computer like image to play there, you need to use motion tracking capabilities to insert an image over that green area.

>>If you have an area that is already green, in the foreground, such as you described, then this is not a valid use of Keying.<<

I think he wants to insert images into the green matte on the forground screen. That's totally do-able. Any area that is your target colour (green) can be replaced with your insert vision.

Here's a tute on green screen in FCP HD to get you started [www.kenstone.net]

Green is much better than blue cause digital cameras pick up a wider range in Green that they do in Blue.
In film its the other way around which is why digital shoots are mostly Green and film are mostly blue.

I would not under any circumstances shoot on DV and absolutely never on HDV which is even worse.
Shoot on Digi Beta (or any 10-bit camera) and you will save a lot of time and tears.
And if you have acces to shake, key in shake.
Even if you would have to learn from scratch it would be faster and the results would be better than if you use Final cut or After Effects.

Johan Polhem
Motion Graphics
www.johanpolhem.com

Is the camera STILL?

Are there any moving objects (like a person's silhouette, in front of the screen) that overlap the edges of the screen's shape, or is it a clean rectangle?

If it's clean, and still, a matte will do you just fine. If not, it's going to be a frame by frame experience...

I have chroma-keyed DV material, and it was really tough to get all the blue out of the remaining image and keep color and contrast looking healthy. I made it passable, with some serious help from one more knowledgable than myself at the time, but the color space of DV is just not roomy enough...

best of luck,

Marla