Free Greenscreen and Tracking Plates
VFX Supervisor Scott Squires’ blog “Effects Corner” links to some nice and freely available greenscreen footage from Hollywood Camera Works. I’m probably the last guy to discover these, but nevertheless the plates are a great training resource. Each shot has some notes about possible keying and matchmoving problems.
And by the way, Scott also has some great articles on various areas of VFX like pre-production, workflow and shot breakdowns.