Senior Product Marketing Mgr.
Advanced Post Products
Avid Technology, Inc.
STEP 1: Create a matte key
Start with a simple timeline that has just one video track. In our example, we have a close-up of a B-17 bomber. The first step in the process is to create a matte key that will be the foundation of our blur. Under the Key category of the Effects Editor palette you will find AniMatte, a set of intraframe tools for creating custom matte shapes. Apply the AniMatte effect directly to the clip you want to blur.
STEP 2: Shape your blur
Open the Effect Editor and select the rectangle drawing tool from the shape creation tools. A gradient blur can be any shape you want, though in this case, let’s focus on the lower part of the screen. Click and drag over lower third of your image. This will create a matte that knocks out anything outside the shape. Since we want our blur to ramp out to the "focused" part of the image, we need to feather the edge of our matte key. Under the Feather parameter in the Effect Editor, adjust the feathering and bias controls to create a smooth gradient on the edge of your matte.
STEP 3: Export your matte to the desktop
Under the File menu, click on the option to Export Matte PICT. Once the matte is exported, you can leave the effect editor and remove the AniMatte effect from the timeline.
STEP 4: Pull in your matte key
Next we’ll import the graphic back in as Matte Key with Alpha. Simply drag and drop the exported graphic to a bin. This creates a source that you can edit right into the timeline. Add a second video track and cut the matte key in over the original clip.
STEP 5: Unlock the entire 3D toolset
With the blue bar parked on the effect, open the Effect Editor and find the parameters for adjusting Matte Keys. As you can see, there aren’t too many matte key options here- that is, until you promote your effect to a 3D Warp effect. In the lower right-hand corner of the Effect Editor is the Promote to 3D button. Press that and the entire 3D toolset is at your disposal for adjusting the matte. You’ll use only two parameters in this case, Defocus and Foreground.
STEP 6: Tweak and play
Once in the 3D tool, the first thing you need to do is turn on the Swap Sources switch in the Foreground parameter. This will prevent you from keying out the non-blurred part of the image. To adjust the blur itself, use the drop-down menu in the Defocus tab, selecting KeyBlur. This will tell Media Composer to use the matte key as the source for blurring the image. (By default, the amount of blur is set too high for what you’d want here.) After that, all that’s left is to leave the Effect Editor and hit play. There you have it: quick and easy gradient blurs without ever having to leave Media Composer itself!
Matt Says Keep In Mind…
Graduated blurs, often seen in music videos and commercials, have become a popular stylistic effect. Blurring the lower third or half of the screen can work on many different levels, from helping titles and graphics pop or directing the viewer’s eye to a specific part of the screen. Sometimes, though, using a blur just looks cool. Whatever your reason for using this effect, you can now create graduated blurs quickly and cleanly inside Media Composer with a new set of integrated tools. These tools are even more powerful when used in tandem. In this example, I’ll show you how to use AniMatte and 3D Warp Effect. Try out your own effects by combining AniMatte with the new Motion Tracker, or Paint with Color Correction.
Avid Technology, Inc
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Tewksbury, MA 01876
About Matt Feury: Since joining Avid in 1994, Matt has provided consultation to film and video professionals around the world. He has also worked in sports television for over a decade and continues to work on projects of personal interest as a freelance editor.