Greenscreen camera recording

I know i've probably left it too late, but a few kids want to do a Nativity play for the local church on christmas eve, the snag is they have to pre record it and have asked if they can greenscreen it, I had no problem with that, we have the screen etc but what cameras best for doing it?

Every camera I seem to use ranging from a Canon xm2 to a HD Logitech Sphere camera all seem to be really pixely... will it matter if I use the HD Sphere Webcam to record and then edit on Vegas Pro? as long as I get the chroma keyer thing right it wont leave green splodges?

If you get what I mean, I generally confuse myself :eek:

I've only tried basic chromakey filming but the key is to get a good 'green screen' and get the lighting right, if you do that then you can get some good results. I used any software to record to an avi then used the free WAX video program for the greenscreen bit. My 'green screen' was a green plastic table cloth from The Range, seemed top work OK, not the best but I'm a cheapskate! Inscructions for how to chromakey with WAX can be found on the web. The software allows you to select any background colur being used but green and blue works best. Hope that helps.

The lighting is the key thing - if it's too patchy then the green screen will appear different shades of green to the camera because the lighting intensity across the scene isn't the same. We used to use a wall painted in a shade of green brought off the shelves of B&Q - did the trick for us. Also used to use 500w workshop floodlights to light it with because they're cheap and bright!

Mike.

Yup, lighting is the key. That's why Lighting Technicians on movies have a string of letters after their name. Watch out for shadows on the screen.

One technique that seems to be gaining popularity is not to have a green/blue screen at all, but a curtain made of reflective beads. A ring of blue/green LEDs around the camera lens gives the appearance that the background is blue/green and the lighting is much less critical. The weather on certain BBC regional programmes is done this way.

The other thing to investigate is whether the software you are using can do a "garbage matte" to ditch the green splodges. You may also have some tolerance values for how close to the reference shade of green it has to be to be disappear.