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How to make this film – Part 2

After Effects

Import the footage into Adobe After Effects. The scene file above will only load into After Effects version 5.5 or above. The techniques mentioned below will work in earlier versions though

Set up the back plate shot behind the main action. Edit all the shots to get the timing right. You should end up with something like this:


We’re going to start on the shot called behind chair. It only needs a static mask. Create a mask by clicking on Rectangle Mask and dragging over the area you want to mask. Use the Selection Tool to move the mask points around and invert it so that it masks out my body. Increase Mask Feather to soften the boundary between the main action and the backplate


Repeat this for the other shots of me appearing


The next stage is to remove my head from the shot where I walk in. I made this easy by wearing a rather attractive green collar. That way all I need to do is key out the collar and create a garbage matte (a rough mask) to get rid of my head without having animate the mask frame by frame round my neck


Select the head less layer and choose Effect > Keying > Color Range. The Effect Controls window should pop up. This part is a little fiddly (especially because the footage is on it’s side – damn!). Click on the Key Color eyedropper icon and select the green collar in the Effect Control preview window. Then select the Plus (+) eyedropper icon below and click on the slightly different greens.


Eventually you’ll end up with this:


Now you need to add a mask to remove my head. As I’m moving you will need to animate the mask using keyframes. Do this by clicking on this icon on your new mask:


A little diamond will appear on the mask on that frame in the timeline. Move the Time Marker through the frames until you find a big change in speed and/or direction. Move the mask points to the new position. Notice this creates a new keyframe automatically. If you move the Time Marker between these two points you’ll notice the mask moves from the first position to the second

Repeat this until my head is rubbed out. Set a few keys to begin with, then go inbetween these keys and adjust accordingly, making the mask follow my head

Eventually you’ll finish, perhaps adding more masks with more feathering as you see fit. Make sure you’re constantly previewing and tweaking as necessary. If the movement is fast and blurs, keyframe an increase in the feathering and add more mask keys. Below is a GIF anim of the keys I used (without the inbetweens):

Now select Composition > Make Movie and note the name of the output file. You can then load this into your GIF anim creator, e.g. ImageReady . Alternatively, if you click on Output Module in the Render Queue window you can choose to output your film as an Animated GIF rather than Video For Windows. Selecting this option does not give you the control a dedicated GIF optimiser has, but is useful nonetheless

Don’t worry about some of the keys in my example file falling between frames, this is because I had to halve the frame rate of the rushes to make the file small enough to download. The original used the 25fps PAL resoulution video straight from my camcorder

29 March, 2005