This clip scales down to 33.3% to fit the image. You now know you can scale this clip
between 33.3% and 100% and maintain quality, while still filling the frame.
Turn on keyframing for Scale by clicking the Toggle Animation stopwatch button for
Scale in the Effect Controls panel.
Position the playhead over the last frame of the clip.
Click the Reset button for the Scale setting in the Effect Controls panel.
Scrub through the clip to see the result.
This creates an animated zoom effect for the clip. Because the clip never scales to more than
100%, it maintains full quality.