In my years of using Final Cut Pro, I’ve stumbled across the question myself, “Do I need to render before I export in Final Cut Pro?”
Short answer: “No.”
Now, I’m not going to get too deep into what rendering is, but rendering is basically FCP’s way of making preview files for you to view. Sometimes, you can’t view heavy effects or mismatched codecs in your sequence in real-time, so FCP creates render files that allow you to view the clip in real-time.
But, FCP does NOT need these render files to export. Yes, if you create render files, it will use them to speed up the export process, but if you do not create them, FCP will do so in the background while it is exporting.
I usually render everything for a final 100% real-time viewing, but there are rare occasions where I have no need for render files. Such as a 30 minute speech that I am not cutting, just simply placing text and graphics over the entire thing. The text and graphics, once placed on top, will show me that a render is needed to view in real-time. But I know I don’t need to watch the entire speech, so no need to waste time and render. Simply export (CMD+E) and everyone’s happy.
Here’s a setting that not many editors know about: “Unlimited RT”
It’s a setting found in the timeline, that forces FCP to play as many frames as possible when your effects exceed the processing power of your computer. Final Cut Pro does this by spending time to process some frames in real time while skipping others completely. It’s not available for all effects and codecs, but if it is available, I always enable it. As opposed to Safe RT, Unlimited RT will change your red render bars to orange, meaning that it will drop frames and quality during these segments to achieve real-time playback.
It’s a pretty cool feature. Depending on your system, you may get a pretty decent 12-15 fps playback. That’s enough to quickly check your effects without rendering. On an old MacBook Pro, playing full 1080p ProRes 422 files, I can only playback about 2-3 fps. So it’s not very usable in that case.