As you learned earlier in this chapter, you can animate any effect using a process called keyframing. In general, there are two methods for keyframing an effect property: rubberbanding, and in the Effect Controls window. Although you can switch among keyframing methods freely, you’ll find that each is better suited for certain types of effects.
Rubberbanding (adjusting keyframes in a clip’s property graph in the timeline) is ideal for making adjustments to opacity and volume values—not only because this approach is time-tested and familiar to many users, but because these values are easy to understand in graph form (Figure 10.8). When the graph goes up, the opacity or volume value increases; when the graph goes down, the value decreases. Properties like rotation, for instance, don’t translate well to a vertical graph (and others don’t translate at all). Moreover, adjusting opacity and volume requires only a single property graph, whereas motion effects and many filters include several parameters you need to adjust.