Hi,
You need to follow what is called the ‘THREE POINT EDITING RULES’
Either set an in and out point on the tape to be mastered via the Edit to Tape window. Then Create an in point on the clip to be mastered.
Or vice versa, an in and out point on the clip to master and an in point on the tape via the Edit to Tape window.
Final Cut Pro automatically calculates the fourth point.
grafxflow
grafx that flow!