I'm shooting a short on my HVR V1E, and editing with FCP.

In one of the scenes, my main protagonist is standing by a road, and I would like to have the traffic behind her accelerate (speeded to 1000%) whilst she remains in real-time so to speak.I assume that this requires some kind of layering, but I don't know exactly what technique to use/ where to look for advice - So, if anyone can help, it would be greatly appreciated!

Cheers.

John

That's a job you've just assigned yourself. Most likely you'll have to mask her frame by frame if she's standing in front of the traffic you want to speed up. That's a big job.

Usually this effect is done with carefully lit chroma-key work. One way is to bring a portable chroma key screen to the location and shoot the talent using natural lighting against the screen. Then the screen is taken away and the camera shoots just the background for as long as needed.

Unfortunately I think William is correct. I don't know any other way to do it. Don't throw out the possibility of re-shooting it, unless that is truly not an option.

If you do end up masking, it is a great learning experience, though very time consuming.

JS

Thanks alot guys!

Sorry my post was unclear. In fact, I haven't shot this yet. The shoots coming up in a week or so.


Looks as if Chroma keying might be the way to go, then. So is it usually possible to acheive this with daylight and no additional location lights? I have knightmarish experience of chroma keying in stop-motion animation, hence my hope that layering would be the way to go - but if daylight will suffice then this sounds like an attractive option.

I really appreciate your responses.

Best,

John

Daylight will work fine, it will light the chroma screen way flatter than studio lights but you'll have to deal with talent shadows on the screen which will be stronger than in a studio. The bigger the screen the better as you can have more distance between the talent and the screen. You should look for some reflectors for the talent and the background.