Using the Shift Fields Filter
When you add a clip to a sequence, Final Cut Pro checks the field dominance settings
of both to see if they match. If both the clip and sequence are interlaced but use
opposite field dominance, Final Cut Pro automatically adds a Shift Fields filter to the
clip so that the clip field dominance matches the field dominance of the sequence.
In most cases, the Shift Fields filter is applied automatically, so you rarely need to apply
this filter yourself. However, you can modify, add, or delete the Shift Fields filter just as
you can any other filter. The Shift Fields filter is located in the Effects tab and Effects
menu within the video filters Video category.