Please take a look at the 'Brake Check'
advert on this page.
How is the time laspe effect using the one person in real time while the action behind him is greatly sped up.
For the life of me the guy does not look superimposed.


http://www.jehproductions.com/work.html

Well, this guys are not moving, so i suppose they where shot in same place without people first and later added to the footage by masking all out except them. Like that road sign in first seconds (of course it could be timelapsed or keyed)

Now that you have made me look really colse, I think you are right.
That is one crisp and clean key.

Now that you have made me look really colse, I think you are right.
That is one crisp and clean key.

hey we all here to share - we are like one giant international brain

perhaps -shoot subject & background at location
bring in a small 5x7 green screen behind front subject ..green screen does not fill the frame- just enough to get clean key of subject ..
use same camera framing for both subject shot and background..
so it's 2 shots ..
1- subject with partial green screen .when finished leave camera same set up and remove green screen ..
2- shoot scene with extra's background time lapse ...

I think Don's got it, the subjects are moving slightly, that slight stand still wobble that we all get LOL. but I think its a full green screen.