The joy of traveling matte

Take a look at this video, then read further for some discussion.

Hats in the Ring editing demo from Joe Dzikiewicz on Vimeo.

In my latest film, “Hats in the Ring,” we had a scene where there were photos displayed on a computer. To do this, we put a green screen on the computer and merged the photos in later. This led to some interesting challenges.

There were two shots in which the green screen was visible. In the first, I locked the camera down on a tripod because I knew that I would have trouble matching the movement of the foreground on the pictures. So I was able to cut out the green screen, put the necessary pictures underneath, and it looked great.

Alas, in the second scene, I shot handheld. It didn’t occur to me the day of shooting that the green screen would be visible and I’d want a photo displayed on it. So the foreground ended up shaking a bit, and when it came time to add the photos to the background, I found it was beyond my editing abilities. (Especially because I got around to this bit of editing at 2:30 on Sunday afternoon and I had to deliver the movie by 7:30 that evening, given that it was for a 48 Hour Film Project.)

Take a look at the first version in the video above and you can see the problem: note how strange the Jefferson picture looks in the second shot. It’s interesting how our eye is drawn to these minor problems in movement, and instructive about what you can’t get away with in filmmaking.

So I ended up with a compromise, and that’s the second version. I just left the screen black. And I turned the screen black at the tail end of the previous shot (the one shot on a tripod) because to do otherwise would have looked like a continuity problem.

But it wasn’t ideal. So this week, I learned a new trick. It turns out that there’s at least four good ways to do what I needed to do in After Effects. I could track the movement of a point in the original shot, then tie that movement to the underlying picture. And voila, the underlying picture followed the movement of the outside shot.

One of the things I love about filmmaking is that there is so much to learn, and I do like learning new things. And this week, I climbed a little higher up the filmmaker’s learning curve.