You usually put the frames on top of each other in two different layers. You most likely have to key out the first layer. For example: THe scene with the train you said ealier, is most likely doen by shotting a car driving over the tracks and then shotting the train. THe clip with the car goes on a top layer and the clip with the trian goes on the layer below it. The car in the clip with the car is then keyed out, so it has no background. And then, it looks as if a car were dodging a train.

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When the script writing is done, the work has just begun. When the filming is done, the work has just begun. When post-production is done, the work has just begun. When the distribution is done, you decide if the work is done.

so how is it keyed out, like what type of keying would be used?

Depends on how you shoot it. If it's CGI you'll have an alpha channel, if it's real you'll use a blue/green screen or rotoscope or similar.

As for combining them, you need a compositing program.

Keying can be done with chroma-keying and masking (aka- greenscreening and matte).

An example of a compositing program is Adobe After Effects and Eyeon Digital Fusion 5.
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When the script writing is done, the work has just begun. When the filming is done, the work has just begun. When post-production is done, the work has just begun. When the distribution is done, you decide if the work is done.

Yeah, I use Fusion 5, but only because I got it cheap :).

ok so how would i do it in after effects. Let's say i had two frames. One was me just standing there, and the other frame is me walking up and punching myself standing there.

I know this is time consuming, but...

First you import your two clips. One with you just standing there, and one with you punching nothing. Put the one punching nothing on the second track, and the one with you just standing there on the first track. Then you have to select the pen tool, and draw around the you in the clip with you punching. You have to do this for every frame and motion. After the you are all cut out of every frame, you are done. When you play the animation, it would seem as if you were punching yourself.

It is really simple, just very time consuming.

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When the script writing is done, the work has just begun. When the filming is done, the work has just begun. When post-production is done, the work has just begun. When the distribution is done, you decide if the work is done.

It is not as bad as Director958 makes it sound because if you have the camera on a tripod for both clips the background will be identical. So you can mask out half the screen for the bulk of the scene and only really have to trace around the part where the "you's" overlap.

RJSchwarz
San Diego, CA

I am sorry this is a little of topic, but, MarkG, how cheap did you get Fusion 5?

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When the script writing is done, the work has just begun. When the filming is done, the work has just begun. When post-production is done, the work has just begun. When the distribution is done, you decide if the work is done.

Well, I got DFX+ 4 free with a Lightwave upgrade, and then Eyeon offered an upgrade from that to the full Fusion 5 for... actually, I don't remember how much, but I think it was under a thousand pounds (plus tax). So when I said 'cheap', I really meant 'about 50% off the full price', not $50 from a shadey guy in a dark alley :).

To be honest, I haven't used it enough so far to justify that amount of money, but the more I use it on different projects the more I can see myself doing with it in future. Just being able to paint out annoying cables and light reflections that we missed on low-budget shoots where we didn't have time to check for them as we were shooting is a big benefit, and you can do a lot with the color correction tools. The current short I'm editing (fifteen minutes long, shot in about eight hours) looks a heck of a lot more professional than it should thanks to Fusion.

Also, it's really easy to some of the things that you see on TV in commercials: for example, that one where there's some guy moving empty picture frames around and as they stop moving the frame 'picks up' part of the background before they move on, which is trivial to do with tracking and merging. Similarly a shot I had to do years ago where I had to put a 'TV picture' onto a guy's watch which was supposed to be able to receieve CCTV images took an age in Premiere but would be easy in Fusion.

cool thanks, i'm going to try it out...one thing though, back in the day before digital editing, how was it done? I heard that the editer would just put the two frames on top of each other. If this is true, couldnt i just import both frames into after effects and use the multiply view to simmulate one frame on top of the other?

Before digital editing it was done with great difficulty :). They'd have to make a physical matte image from the footage and use that to combine multiple film images optically.

Much harder than loading it into a PC and clicking a few buttons.

BTW, this is quite a cool no-budget video made in Fusion with footage from a JVC HD100:

http://www.box.net/public/static/q3ubp6ostx.wmv

With a 'before and after' shot:

The skyscrapers were a different location, most of the laundry is CG, the 'crane' is purely virtual, etc.

There's a discussion thread at:

http://www.dvinfo.net/conf/showthread.php?t=75318

Which gives some more details on how some of the effects were done: basically they created a simple 3D world and superimposed the video footage onto parts of that world as textures so they could move around in it.

well i did what you said and here's my first attempt, the sound is a little off because youtube sucks...

http://www.youtube.com/watch?v=q5jxLNsNRXg