A Few Random Questions

Can you lot help me by answering these questions for me?

1. What does it mean in a show by "ad-lib"?
2. In Bo' Selecta, what did the real Davina do to make the Avid Merrion Davina "not know she's live"?
3. When using a blue screen (or part blue screen) how does the camera know what is behind it, when the blue is taken away during editing?

Thanks

http://en.wikipedia.org/wiki/Ad-lib

Ad lib is to make stuff up as you go along.

As for number 3, the camera is blind to the blue so it doesn't see it. Therefore you replace the colour blue with the image of your choice - weather forecast, credits, dungeon, etc.

There's a nice little clip here:
http://www.knightmare.com/behind/kellyvision/index.htm

Which, while its a few years old, will still give you the general idea.

I don't blame you if you haven't, but in the behind the scenes of Bo' Selecta Vol. 3 DVD, when they sort out The Bear, Leigh's head is poking through a blue sheet, but the real set is behind it. I want to know how it can remove the blue but make it seem there wasn't one there in the first place. I'll put up a capture soon if I can.

I think i see what you're saying. The camera dosen't know what is behind it, the blue screen when in editing is taken out and you're basically left with a hole, it dosen't know what is behind it. In editing when you've taken out the blue you just put something in its place, such as a weather map, beach scenery whatever. Wherever the blue was in that scene the placed footage will now take up the place where the blue used to be. It's a very good technique!

No. 2 - don't think Davina did anything - it's nothing more than a piss-take. The bloke who plays Avid Merrion is a good friend of Dermot O'Leary and made a number of apperances on BBLB before Bo Selecta began!


No. 3 - a question of my own. With computer generated backgrounds, is it possible to kind of regenerate them so record something once with one background, then edit it to have another background.

(if that makes no sense I guess I'm kind of asking if the background has to be added live, or can it be recorded then added later!)

Sort of layer effect, sticking one image on top of another as it were?

I dare say in theory it should be possible.