Super Imposing

reece.b wrote on 7/18/2003, 11:43 PM
What I have done is used a white sheet as the whole background to act as a green screen if you like, now what i want to do is super impose a image on the white area with out it interfering with the person. Like so the person won't look transparent.
I've tried going through the Compositing mode list but they screw up the picture of my actor.

I want the video to turn out so it looks like the actors standing at the place in the picture.

Comments

snicholshms wrote on 7/19/2003, 1:51 AM
Use the chroma key F/X. Eyedropper on the white background. You will probably have a problem with white, though...it's in a lot of pale colors and the chroma may not work too good.

reece.b wrote on 7/19/2003, 6:06 AM
Whats a good color to use as a background other than white?
Chienworks wrote on 7/19/2003, 7:31 AM
Use a moderately strong color that doesn't occur in your subject. Blue and green are often used because they rarely occur in human subjects, but any color will work. If your subject is wearing a bright blue & green suit (ewwww), then maybe a strong purple color would work.

Try to avoid extremes in brightness. One problem you will probably have with the white sheet is that it may mess up the auto exposure on your camera and make the subject darker. A black background will do the same thing in reverse, making the subject too light. By the same token, if your camera only has auto white balance, using a super-saturated background wouldn't be good either because the camera will try to balance on that, casting the opposite color on your subject.

Whatever you choose, make sure the background is very evenly lit. If part of the background is lighter or darker than other parts then you'll have much more trouble getting the chroma key to work.
kameronj wrote on 7/21/2003, 8:41 AM
I tend to agree with chienworks....Chromakeying is a funny little beast to get used to.

I've been playing around with a few techniques to get a good one going, and you have to take a few things into consideration when doing this. If it is a before hand process...your background has to be evenly lit. Shadows kill the process.

If it is after the fact, it can be done, but depending on the video shot...it can be tricky.

I would suggest "playing around" with different ways to do it and get a good feel for how it is done. It is relatively "easy"....once you get use to it.
BillyBoy wrote on 7/21/2003, 3:39 PM
People commonly have BLUE or GREEN eyes. Even me. <wink>
doormill wrote on 7/24/2003, 11:52 AM
If you have a few bucks to spend take a look at this it will help you do this.

http://www.seriousmagic.com/proverview.cfm


Have a good day!!!