Let’s see how a long steadicam scene is made and how it looks like then in the final shot with Hugo Cabret as example. Try to watch both videos at the same time and sync it for a better effect.

Behind the scenes video:

Final shot:

Hugo is a 3D movie shot using the particularly heavy (+80lb) Arri Alexa, that's why you can hear the cameraman exhausted at the end of the behind-the-scenes video. Their 3D Steadi rig should look like this. Kudos to the cameraman!