Adobe Premiere Pro 2.0 [Electronic resources] نسخه متنی

Using matte keys: Lesson 13-5

Matte keys cut "holes" in one clip to allow portions of another clip to show through, or create something like cutout figures you can place on top of other clips.

The nomenclature can be confusing. Matte keys are not the same as color mattes like the orange matte you used earlier in this lesson. However matte keys generally use matte graphics that you create to define the areas you want to make transparent or opaque.

There are two basic types of matte keys:

• Garbage Four-, eight- or 16-sided polygons, so named because you typically use them to remove something you don't want in the video. You move their vertices to define the outline of an area you want to display.

• Graphic You create a shape that you want to key out or key in using a graphic or another clip. These include: Difference, Image, Remove, and Track.

In this mini-lesson you will work with the Sixteen-Point Garbage Matte Key and the Track Matte Key. I'll briefly explain Difference, Image and Remove. You'll start by trying to use the Luma Key. You'll see it has some limitations that a garbage matte can help you overcome.

Note

When you select the second clip, the cat looks unchanged. In fact what you're seeing is the cat's right eye from the clip in Video 3 and the rest of the cat in the clip on Video 2 revealed when you created the garbage matte cut-out on Video 3. The reason you are applying this garbage matte to two instances of the same clip is because you can't apply this effect to the same clip twice. Once you create a cut-out, you can't create another one elsewhere in the same clip.

You've created something that looks too much like you cut holes in the sky. There are a few ways to remedy that. Here are four:

• Switch the Luma Key back on. That gives the eyes an orange cast that matches the sky.

• Apply a blur effect to the two cat clips.

• Apply the Tint effect and Map Black to the dark areas of the sky, and Map White to a light orange area of the sky.

• Use the Orange Matte with opacity in a five layer composite.

I took that latter approach in the example in the Lesson 13 Finish sequence. I also applied motion to the cat photos to have the eyes appear in the upper right corner, and I used the same garbage matte parameters (Copy/Paste Attributes) used on the cat photos on the Orange Mattes to have them fit exactly over the cat's eyes so they wouldn't add an extra orange hue to the sky. I finished the whole thing off by applying Cross Dissolves to gradually reveal the cat's eyes.

Mattes that use graphics or other clips

There are four Keying effects that fall into this category. You'll work with the Track Matte because it's the most useful and works the best. Here's a quick rundown on the others:

• Difference Matte A very difficult effect to get to work smoothly. In theory you use it to place multiple actors/animals/objects that could not all be in a scene at the same time in the same set. You have to shoot the various shots using the exact same lighting and camera angle and you need to work with high-end video to have a chance of making it work. It's best to stick with green/blue screens.

• Image Matte Works just like the Image Mask Video Transition. You apply it, load up a graphic or still image, and the effect makes dark areas transparent and light areas opaque. It's a static effect with limited usability.

• Remove Matte Specifically for graphics that when used in keyed shots have something akin to a thin halo around their edges. Apply this key to remove it.

Using a Track Matte key

A Track Matte key works like an Image Matte but has several advantages and one obvious difference. What makes it different is that you place the mattea still image, graphic or something you created in the Titleron a video track (thus its name) rather than apply it directly to the clip.

A Track Matte uses the clip on a separate track to define areas of transparency in the selected clip and reveal whatever is below it on a sequence. Its huge advantage is that you can animate the matte. For example, you can use Motion's Scale parameter to gradually reveal the matte or move it on the clip to follow action. The latter application of the Track Matte is called a traveling matte.

Just about every older movie involving "impossible" motionspaceships, Superman in flight, or giant spidersused traveling mattes.

You will do both types of Track Matte Keys.

Note

When using the Track Matte Key effect, place the track matte clip on a video track that is above the clip you are applying Track Matte Key to.

Lesson 13-2, you do not have to un-Enable the clip you use in the Track Matte Key effect. When you select the Matte video track, Premiere Pro automatically disables only the portion of the track used in the Track Matte Key, meaning other clips in the track will be processed normally. This is a terrific feature that saves a bunch of steps and allows you to use the selected track for other clips elsewhere in the sequence.

Making a traveling matte

You will use this effect time and time again. It's a great way to follow action. In this case you will tint the entire shot except for the cantering horse. You will use the Lesson 13 Finish sequence.