Final Cut Pro – A Secret Way to Change the Speed of a Clip
… without changing its duration. Here’s how.
Christine Steele showed me this trick.
The problem with doing a constant-speed change to a clip is that it always changes the length of a clip; which messes up all the edits you’ve done in the Timeline.
That is, unless you know this secret technique:
Put your playhead in the clips who’s speed you want to change.
Press Option+Command+F. This loads the clip in the Viewer, matching the position of the playhead, without setting any Ins or Outs.
Note: DON’T move the playhead at this point.
With the Viewer selected, use Modify > Speed to change the speed of the clip.
Drag the clip from the Viewer to the Canvas and drop it on top of the blue Replace Edit overlay menu.
The original speed clip in the Timeline is replaced with the changed-speed clip in the Viewer.
Note: Because the clip is now running at a different speed, you will see either more, or fewer, frames that the original clip. Where you first put your playhead in the Timeline determines what portion of the clip you’ll see.
Courtesy of Larry Jordan