Apple Final Cut Pro 5 - Manual (Page 1055)

268 Part II Project Interchange
Smoothing Keyframes With Bezier Handles
The keyframes of some motion settings and filter controls (but not audio volume levels)
can be smoothed. When you smooth a keyframe, one or more Bezier handles are
“attached” to the keyframe. These handles define the Bezier curve applied to a
parameter’s interpolation from one keyframe to the next. This allows you to modify the
acceleration and deceleration of the change from one keyframe’s value to the next. The
velocity doesn’t cause the effect to happen faster or slower; the overall speed of an
effect is determined solely by the distance from one keyframe to the next.
For example, if you space keyframes 2 seconds apart in the Rotate setting, the resulting
rotation lasts 2 seconds. If you apply smoothing to one of the keyframes, the total
duration of the rotation remains 2 seconds, but the rate at which the clip rotates to full
speed and then slows down to a stop is different over the course of those 2 seconds. If
you move the two keyframes closer together, the rotation happens faster; if you move
the two keyframes farther apart, the rotation happens slower.
Two keyframes with
no smoothing
Bezier handle on one
side of a smoothed
keyframe