[ This article was first published in the January, 2008, issue of
Larry’s Final Cut Pro Newsletter. Click here to subscribe.
Updated June 2008. ]
The problem with adding a constant speed change to a clip is that it always changes duration when you change the speed of a clip, thereby pushing everything out of whack downstream.
Here’s a very slick technique that prevents that problem.
But, first, a bit of background. By definition, if you change the speed of a clip it MUST change duration if it is going to play every frame from the In to the Out.
However, if you are willing to not play every frame, then this technique works perfectly. Here’s how:
- Put your playhead into the clip who’s speed you want to change.
- Position your playhead on the frames you want to keep. Those frames that are furthest from the playhead will be lost in the speed change (assuming you slow the clip down. If you speed it up, frames prior to the In or after the Out will be added to the clip.
- (Here’s the secret trick!) Press Option+Command+F. This loads the source clip into the Viewer (notice there are no sprocket holes in the playhead scrubber bar at the bottom of the Viewer). This acts like a Match Frame, but without setting an In or an Out.
- Select the Viewer
- Choose Modify > Speed and change the speed of the clip. In this example, I’m slowing it to 50% normal speed.
- Without moving the playhead in the Viewer or the Timeline, drag the clip from the Viewer to the Canvas and drop it on top of Replace edit.
- POOF! Your timeline clip has changed speed without changing duration (see the green render bar at the top of the clip?)!
I use this trick frequently and still marvel at how well it works.
UPDATED – June 2008
Ed Yost sent in the following, after reading my article:
In response to A Better Way to Change the Speed of a Clip, January newsletter.
I had been working on a show for HGTV that was more about the personalities of the people than that of a how to show. The show was edited in a comedy style. Often the People would rush into and out of frame or run up to camera from some distance off. As editor’s we would speed up entrances and exits etc. every opportunity, but always had to work around dialogue and to beats of music.
A technique for doing speed changes and keeping my timeline in sync I found very helpful follows.
- Edit into the timeline the dialogue where you want it to fall or hit a certain phase of music.
- Create a video track above that will only be used for speed changes, containing no other video. This is kind of a video track just to do rough work in. You may want to create two audio tracks also, for example if you wanted to hear the person running to camera on a concrete sidewalk.
- If you have a two-second phrase of music before the dialogue for the talent to run up to the camera that took, say, 20 seconds to shoot in real time, trim the shot to cover just that 2 seconds of music.
- Move the video clip up to the empty video track, and move the audio down to the work tracks.
- Trim those pieces until I found the frames I wanted the effect to start (20 secs.)
- LOCK all other video and audio tracks (shortcut: Command click the track locks for that track) choose Modify > Speed select a duration of 2:00.
- Unlock the other tracks
- Put the video & audio clips back to the original tracks and you will see a speed change with a perfect match frame. This also works better when you up-res the piece in an on-line session.
As a note: when moving tracks of video and audio I generally do not have them linked.(never edit with linked pieces & snapping on) But. When doing the speed change have them linked so the speed change happens to both video and audio simultaneously.
Larry replies: Thanks, Ed, for sending this in. I love reading about new ways to do things.
