Apple Final Cut Pro X (10.1.2) - Manual (Page 212)

Chapter 9 Add transitions, titles, effects, and generators 212
How transitions are created
Transitions require overlapping video from the clips on each side of the edit point. A one-
second transition requires one second of video from the end of the left clip and one second of
video from the start of the right clip. When you apply a transition to an edit point, Final Cut Pro
attempts to use additional video from each of the clips to create the overlap. These additional
(unused) sections of clips are known as media handles. The following image shows a clip with
media handles on each end and a clip with no extra video, or media handle, at its start.
Clip selected in the Browser
No start media handle
End media handle Start media handle
End media handle
The media handle video may not be appropriate for use in a transition. For example, if the video
includes unusable video such as a slate, it will be visible in the project.
You can set the default duration for transitions. See Set transition defaults on page 213.
The illustration below shows how transitions are created when the clips on either side of the
edit point have media handles. The transition is placed so that it spans the clips; one half of the
transition overlaps each clip. Unused media from the end of each clip is added to fill out the
transition. The total duration of your project is unchanged.
Edit with no transition
Media handle
Clip 1 Clip 2
Clip 1
Clip 2
Media handle
Edit with transition (media handles used)
If one or both of the clips do not have enough extra content (media handles) to support a
transition of the default duration, you are given the option to overlap media in your project to
create the transition.
67% resize factor