[This article was first published in the Feb/March, 2008, issue of
Larry's Final Cut Pro Newsletter. Click here to subscribe.]

One of the questions I get asked a lot is how to manage render files in Final Cut Pro.

The answer is that render files are easy to manage if you understand some key concepts.

Note: "render" has a simple definition, even though it has an unpleasant name. "To render" means "to calculate." Complex effects need to be calculated before they can be played in real-time. It would have been easier for all of us if the programmers had just called them "calculated files," but, no, they needed to intimidate us instead.

Here are the basic concepts behind render files:

1. Render files are contained in the sequence, not the clip.
2. There is a maximum of one render frame for every sequence frame
3. Rendering a nested sequence does not affect the rendering of the clips contained in the original sequence.
4. Changing an effect, transition, or clip visibility instantly deletes all the render frames associated with it. (Yes, they remain as part of the Undo queue, but, essentially, when you alter something that has render files associated with it, the old render files are gone.)

Render files are exactly the same size and format as your sequence settings -- with one exception. With the release of Final Cut Studio 2, and the introduction of the ProRes 422 codec, Apple has added the capability of rendering HDV and XDCAM HD/EX video using ProRes, instead of the native format. Based on my tests and reading, I think this is a good idea.

First, rendering is about 35% faster when using ProRes rather than the native codec. depending upon the speed of your computer and the complexity of your effect. Second, you are creating render files in a higher-quality format, which means that there is less image degradation during rendering.

The only negative to this approach is that ProRes file sizes are four to five times bigger than the native codec. The reason for this is that ProRes is much less compressed than either HDV or XDCAM, which accounts for it's increased speed and image quality.

When you change the visibility of a track, by toggling one of the green visibility lights, you automatically delete all render files associated with any clips on that track. This is because render files are tied to the sequence, not the clips. You've just changed the content of the sequence, which affects the render files.

A much better approach is to make individual clips invisible by control-clicking a clip and unchecking Clip Enable. You will still lose the render files associated with that specific clip, but you won't lose the render files for an entire track. (The keyboard shortcut to toggle Clip Enable is Control+B.)

During the course of editing a project you can essentially ignore managing your render files. Final Cut handles them automatically. Similar to the video you capture, render files are stored in your scratch disks, in a folder named after your current project, in either the Render Files folder or the Audio Render Files folder.

When your project is complete, output, signed-off, and paid for, then, you'll need to delete your render files to regain disk space. There's never a reason to archive render files, as Final Cut will recalculate any missing render files. And, in fact, each version of Final Cut brings improvements in rendering, so there's no good reason to retain render files from a project created by an earlier version of Final Cut, as the new version will make them look better anyway.

Unlike Media Manager, which should be avoided by any individual with common sense, the Render Manager works great. Even better, it's easy to use.

Choose Tools > Render Manager to display the window. Render files are separated as either video or audio renders, and stored first by sequence and then by project. Render files are grouped by sequence; within Render Manager you can't see individual effects.

To delete a render file, simply click in the delete column and click the OK button at the bottom of the window.

If the render file was created recently, you'll get a warning saying that deleting render files will empty the Undo cache. In all cases, deleting render files is not undoable.

Larry Jordan is a post-production consultant and an Apple-Certified Trainer in Digital Media with over 25 years experience as producer, director and editor with network, local and corporate credits. Based in Los Angeles, he's a member of both the Directors Guild of America and the Producers Guild of America.

The information in this article is believed to be accurate at the time of publication. However, the author assumes no liability in case things go wrong. Please use your best judgment in applying these suggestions.

The opinions expressed in this article are solely those of the author. This newsletter has not been reviewed or sanctioned by Apple or any other third party. All trademarks are the property of their respective owners and are mentioned here for editorial purposes only.

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