There are several ways to create a video clip in manager.
The easiest way to create a clip of the full duration of a recording is go to the Present tab, then drag the recording directly into the clip bin. This will make a video clip that includes the entire recording.
Alternatively, you can set start and end points as you view your video, then click Create Video Clip.
If you are right-clicking on the recording in the Analyze tab to create a clip, this will create a clip that is only 30-seconds in duration. You can select this clip in the clip bin, then you may adjust the duration in relation to the entire recording.