As you edit a project, you may find that you’re mixing frame rates and even resolutions into the same project. From the strictest technical sense, this is not ideal because it means the differing assets will need to be converted to match the rest of the footage used (a process called conforming). Fortunately, Final Cut Pro X does a good job conforming footage.
Conforming is driven by your project settings, so if you change the codec or frame rate of your project, clips that do not match are conformed. You can also conform an individual clip and even change how the process occurs.
Here are a few rules to remember:
• The original video and audio project properties should match how you want to share the movie with ...