Advanced Video Camera and Editing

Nesting Sequences

In any given sequence, when working with a group of clips, you may want to treat this group as a single object. This task can be accomplished by Nesting, which also allows you to add effects and other time-consuming procedures quickly and easily.

Any sequence can be treated as a clip, which can be inserted into another sequence. The embedded Sequence is called a Nested sequence, and the sequence that it’s embedded into is often called the Parent sequence.

Any group of clips already in a sequence can be converted into a nested sequence, becoming what amounts to a single clip.

Some Basic Nesting

Take, for example, a sequence consisting of three clips that depict the moon rising over a primordial ocean. This sequence requires some thought, so you must think like an editor. An editor thinks in terms of layers. They must ask themselves how the clips are to be layered, taking into consideration the background shot and foreground elements.

To get the right effect, our depiction of the ancient moon rising over Earth's ocean must be layered. In this case, the two primary visuals consist of the moon and the ocean. Now all you need is some imagination. How do you visualise the scene?

For starts, some 4 billion years ago the moon was much closer to Earth and, thus, appeared larger in the sky. This is the scene we’re trying to create. But how do we insert the moon over Earth's horizon? There is no one right way necessarily, but the solution to this problem also requires some thinking.

One possible solution involves masking out part of the sky, which will allow the moon to become visible. Therefore, this effect requires that the clip of the moon be placed in the bottom of the layer, or V1 track. The ocean clip will then be layered on top and made transparent so the moon underneath becomes visible.

First, the bottom layer, which is the moon clip:

The second clip of the ocean is layered on top of the moon clip.

The opacity in the ocean clip gets partially reduced, making the clip of the ocean transparent. However, we can only adjust the opacity for the entire clip, therefore the entire moon is visible even over the ocean.

The moon should be visible only in the sky. To achieve this, we must duplicate the shot of the ocean and layer it on top of the transparent version. This top layer will mask the transparent ocean layer below. But we want the sky to be transparent. So we remove the sky by cropping the image down to the horizon, like opening a door halfway. The moon is now visible to the edge where we cropped. A little feathering to the crop's edge completes the composite!


 Here's what the clips look like in the sequence:

You can see the moon clip at the bottom of the layer. The transparent ocean is the middle, and the duplicated, cropped version on top.

After all that work, we can finally nest the clips into a single object.

  • Select the clips in the Timeline
  • Click Sequence > Nest Item(s)
  • In the dialog box, name the clip and click OK

The three clips are nested into a single clip.

You can still make modifications to your sequence by simply double-clicking the nested clip. A new sequence will open revealing all of the original clips.