How do I make a green screen work?

Question

I bought my mom a Karaoke set. I want to make a green screen and make it work so it has fun background behind it when they sing on it. I found a design for a green screen. What do I do with it once it is made???

Please help.

Answer 1

If you are talking individual pictures, you light it uniformly, take pictures of people in front of it and digitally edit the images to replace the green with transparent then merge the picture over the background image.
If you want a live video picture, then you need equipment that will deliver the video image to a box that removes the green and adds to another image delivered from a background file - a mixer with two video in and one video out.
If you think you can put an image up behind people that is there to see with the unaided eye (no video, no images) that isn't done with a green screen. You need a rear projection screen and a slide, movie, or video projector behind it (because if it is in front, shadows from the people fall on it.)