Fast Motion background combined with Real Time

[Randy Bernard]

I'm looking to create a short video, where the background (people on the street, traffic, etc) is moving at warp speed. But I have two actors moving at normal speed having a conversation mixed in the crowd of people. At a couple of points during the dialog, I would like to slow down the "frantic" background as they continue their conversation.

Imagine busy New York sidewalk where everyone is moving fast except the two people having the conversation.

I first thought of just filming the background...speeding up the velocity in editing. Then greenscreening the two actors.

Other options or examples?

Thanks in advance

[Edward Troxel]

Originally Posted by Randy Bernard

I first thought of just filming the background...speeding up the velocity in editing. Then greenscreening the two actors.

Sounds like a reasonable method to me!

[Bennis Hahn]

Middle of this clip: http://www.sprocketpictures.com/will...s_the_view.htm

I did a similar effect in the middle of this clip. It was all rotoscope work. Locked off shot, shot once for slowmo and once for real time. A lot easier then greenscreen and a lot less fake looking.

[Voitek Nosovski]

Hey Bennis.

Saw your website, stunning work.
Can you please explain how excatly do you achieved this effect in Vegas or if you dont feel like writing this please post which keywords i should use when looking for it. I tried to look up rotoscope but youtube video tutorials are about something quite different.

Let me know, thaks

Voitek

[Randy Bernard]

Hey Bennis,

Exactly what I was looking for in the shot. I agree with Voitek, any more detail you could provide would be greatly appreciated.

I understand that the background and foreground folks would be shot exactly the same locked down angle, position. I would put the background on one track and increase velocity to speed things up.

Are you doing something frame by frame (ie removing the background) to get your guy walking in slowmotion on the track above the background?

[Mark Harmer]

You can do something like this with just one camera, no green-screen, but only for a limited speed-change. I gather the technique is to get the artist to mime to a slow-speed audio playback during the take, while everything else happens as normal around them. The resulting video is then corrected back up to normal speed in the NLE. When you do this, the artist will appear to be moving / playing / speaking at normal speed, but everything happening round the artist (and of course any camera moves) will be speeded-up.

It would only work for limited speed-changes for practical reasons. However, the effect in Bennis's clip is just amazing and yes please - I too would love to know how you did this...you've got me intrigued!

[Voitek Nosovski]

the simple slow motion with lip synch is quiet easy. now compositing two shots of the same place is still a secret to me. i would love to learn how to do this.

[Mike Kujbida]

Originally Posted by Voitek Nosovski

now compositing two shots of the same place is still a secret to me. i would love to learn how to do this.

Check out Matthew Chaboud's Two Cats From One tutorial for some ideas.

[Mark Harmer]

Originally Posted by Mike Kujbida

Check out Matthew Chaboud's Two Cats From One tutorial for some ideas.

Great tip - thanks! I've never tried compositing and once I'd seen the "Two Cats from One" project and worked out what he did, I've avoided tons of proper work by having fun compositing endless bits of video together. I'm used to photoshop and it's a similar process only you get to move the mask around if you want. Very addictive and wonderfully satisfying!