using a greenscreen

[vincelotus1@com]

Is there a tutorial on greenscreen, reason for its use,how & when to use one

[Der_W]

Russell Brown has some nice videos on his website on how to extract models from a green screen: http://av.adobe.com/russellbrown/CS4Masking_SM.mov and http://av.adobe.com/russellbrown/Gre...Monster_SM.mov.
Although I'd rather suggest to use a 50% gray background (that doesn't result in all that much spill and is even a little easier - at least for me).