To achieve the editing technique of starting or ending a shot at normal speed and applying a motion effect in the middle on the Blackbird timeline, follow these steps:

Find the Frame

First, locate the specific frame in the shot where you want the normal speed playback to begin or end. You can do this by scrubbing through the video or using the navigation controls.

Add Cut Point

Once you have identified the frame, add a cut point or edit point to the shot at that position. You can do this by using the Edit Point button, which can also be assigned to a keyboard shortcut for quick access.

Unlink Audio

If you want the motion effect to only affect the video, you'll need to unlink the audio from the video. To do this, click on the padlock icon on the audio track to unlink them. This will ensure that only the video gets affected by the motion effect.

Disable Audio Selectors

On the sync track, turn off the audio selectors for the video clip. This step ensures that only the video will be affected by the motion effect, and the audio will remain unaffected.

Apply Motion Effect

With the cut point set and the audio unlinked, click and hold the Shift key to activate the motion effect trim mode. While holding Shift, trim the clip to the desired speed. For example, if you want to speed up the clip, drag the trim point to the left.

Preview the Result

The result of this technique will be a section of the video with a motion effect in the middle, while the beginning and end of the clip will play at normal speed. The motion-affected section will blend seamlessly with the unaffected sections.

Reverse Technique for the Beginning

To achieve the same effect at the beginning of the edit, you can use the same technique but apply the motion effect trim to the incoming shot at the cut point.

This technique allows you to create dynamic and engaging edits with normal speed sections framing a motion-affected middle section.