Before keying out colors or working with luminance, I want to cover opacity.
Premiere and other nonlinear editors like it have a general operating practice. Video tracks above track 1 trump tracks below them on the timeline. In other words, whatever appears on the highest track covers up whatever is below it. However, the object isn't to use tracks above Video 1 to obliterate what's beneath them. It's to enhance what's down there.
Premiere offers up to 98 of those so-called "superimposing" tracks. Their purpose is for layering (compositing).
One easy way to see compositing at work is to place a video or graphic on a superimposing track. Then turn down its opacity to make it translucent, and let video(s) on lower track(s) show through.
A tool to accomplish this is the Opacity rubberband.
Here's one way to see the opacity rubberband in action. For this exercise, I'll have you place a "super" (text) in a superimposing track above a clip. Then you'll use the opacity rubberband to fade that text in, display it over your clip for a while, and then fade the text out. Your timeline will look like Figure 14.2 by step 8.
Here are the steps to follow for this task:
Place a video clip on Video 1. Any clip will do, but trim it to about 15 seconds to simplify things.
Open the Title Designer (File, New, Title) and create some simple text. Add color if you like.
Save your text (File, Save). It'll show up automatically in the Project window.
Drag the text to Video 2, drag the right edge to make it as long as the Video 1 clip, and expand the Video 2 track by clicking the triangle next to the words "Video 2." By default, the red opacity rubberband track should display (as opposed to the keyframe track).
Even though you have not added a video effect to this clip, the expanded track reads "Alpha Key." By default, all titles have an alpha channel that is enabled when you add them to Video 2 or higher on your timeline. That means the non-text portion of the title screen automatically will be transparent, letting the lower clip show through.
Use the red opacity rubberband just like the red volume rubberband for audio tracks. To fade in the title, drag the start handle down to the bottom of the track.
A couple seconds into the clip, click the rubberband to create a handle and drag it as far up as it can go?to 100% opacity.
A couple seconds before the end of the clip, make a new handle. This anchors the opacity at 100% at that point.
Drag the end point handle down as far as it can go, fading the clip to zero.
Preview your clip. The title should fade up, hold for a while, and then fade down. That's compositing in its simplest form.
Try a similar process with two video clips, but choose your clips with some care. If you select just any two clips, blending the two together can look way too busy.
The purpose of this task is to let the clip on the lower track show through the higher clip in a pleasing fashion. Try to use a clip on the higher track with a distinct bright or well-lit area. For my example, I used some flowers with the sky as a backdrop. Here's how this works:
Drag the clip you want to show through to Video 1 and the clip with the bright section to Video 2.
Expand Video 2.
Instead of fading down the start handle of the opacity rubberband, you'll use the Fade Adjustment too?I've highlighted it in Figure 14.3?to move the entire opacity rubberband line. Select the Fade Adjustment tool, hold down the Enter/Return key, and drag the opacity rubberband down to 50%.
Just a reminder: Holding down the Enter/Return key while dragging the Fade Adjustment tool or any rubberband handle will display the exact percentage of opacity.
Preview this effect. The lower clip should show through the upper clip, especially in the lighter areas of the upper clip. My example is shown in Figure 14.4.