Tutorial: Page (1) of 2 - 05/20/04

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When film is run through the projector time and time again, the sprocket holes can grow in size and the film can warp leading to a shimmy when the film is projected on the screen.  This effect, known as gate weave is popping up in many 3rd party plug-ins.  In this After Effects tutorial, I?ll show how to create one of your own.

With the popularity of film look tutorials ? most recently my Bleach Bypass exercise ? it is time to begin to examine film damage effects.  The gate weave effect can be done by setting a bunch of keyframes by hand, or can be done with expressions.  While we will be using ?My Favorite Expression? (wiggle), we?ll set it gives you a bit more flexibility when needing to tweak the effect or keyframe wiggle properties over time.

For this exercise, I?ll be using a clip from the Artbeats Destination San Francisco collection.

Video clip courtesy Artbeats

Step 1:  Launch After Effects and import your clip.  Drag the clip to the Create New Composition icon in the Project Window.  This creates a comp that is the same aspect and length of the clip.

Step 2:  In order to make our gate weave effect as customizable as possible, we are going to add two sliders that we will then link to with our Pickwhip.  With the clip layer selected in the Timeline apply a Slider Control from Effect>Expression Controls.

Step 3:  In the Effect Controls Panel, rename the Slider Control to Weave Amount.  Right+Click on the Slider, and select Edit Value from the pop up menu.  Set the Slider Range ?to? value to 15.

Fifteen is a pretty large weave amount, but I have set it this high in case you really want your clip to get wonky.  In the Magic Bullet for Editors Misfire (read my review here), gate weave starts at 5 pixels.  Set the Value to 5 and press OK.

Step 4:  Apply another Slider Control effect to the layer.  Rename this slider to Weave Frequency.  This will control how often the frame moves.  Set the Range to 30, and the Value to 7.

Step 5:  With the expression sliders set up, we can now apply the wiggle expression to our clip.  With the clip layer selected in the Timeline, press the P key to bring up Position Property for the layer.

Step 6:  Option+click (Alt+click on the PC) the stopwatch icon to activate expressions for this property.

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