Compositing and Special Effects 670 Figure 13.28. Adjust a keyframe while the playhead is located on a different frame, and the effect's parameter readout will show the value at the playhead position. · Use the incremental controls (the tiny arrows at either end of effect parameter control sliders) to nudge values by + or ­1, or enter an exact numeric value in the parameter's text field. · In the Timeline or Viewer, hold down the Command key while you drag a keyframe. This enables "gear-down" dragging, which allows you to move the keyframe in precise increments. · Shift-drag to change both the value and the keyframe's point in time simultaneously (Figure 13.29). Figure 13.29. Shift-drag the keyframe to change both the value and the keyframe's point in time simultaneously. Using Motion Unlike filters or generators, motion properties are already present on every clip. You can access them by loading a clip or sequence into the Viewer and then selecting the Motion tab. A few of the controls you find on the Motion tab of the Viewer don't have any obvious connection to movement: the Opacity control is located on the Motion tab, as well as Crop, Distort, and Drop Shadow. Some of the tools perform basic image modifications when used as static composition tools, but they also create motion effects when you adjust their values over time. For example, you might use the Rotation control as a static composition tool to display a title at a 90-degree angle (Figure 13.30) or animate rotation by setting incrementally increasing values over time (Figure 13.31).