Apple Color 1.0 - Manual (Page 290)

290 Chapter 14 Keyframing
Keyframe Interpolation
The interpolation method that a keyframe is set to determines how settings are
animated from one keyframe to the next. There are three possible types of
interpolation:
 Smooth: Smooth keyframes begin the transition to the next keyframed state slowly,
reaching full speed in the middle of the transition and then slowing down to a stop
at the next keyframe. This “easing” from one keyframe to the next creates transitions
between color corrections, animated Color FX node parameters, Pan & Scan settings,
and animated user shapes that look and move smoothly and naturally. However, if
you have more than two keyframes, your effect will seem to pause for one frame as
the playhead passes over each keyframe, which may or may not be desirable.
 Linear: Linear keyframes make a steady transition from one keyframed state to the
next, with no acceleration and no slowing down. If you use linear keyframes to
animate an effect that happens somewhere in the middle of a shot, the animated
effect may appear to begin and end somewhat abruptly. On the other hand, if you
are keyframing an animated effect that begins at the first frame and ends at the last
frame of the shot, the appearance will be of a consistent rate of change.
 Constant: Constant keyframes perform no interpolation whatsoever. All effects
change abruptly to the next keyframed state whenever the playhead reaches the
next constant keyframe. Constant keyframes are useful when you want an effect to
change suddenly to another state, such as changing the contrast to simulate a
lightning strike flashing through the window.