About Rendering in Color

Rendering has a different purpose in Color than it does in an application like Final Cut Pro. In Color, all effects-processing for playback is done on the fly, either dropping frames or slowing down as necessary to display your color-corrected output at high quality for evaluation purposes. Playback in Color is not cached to RAM, and there is no way to “pre-render” your project for playback while you work.

In Color, rendering is treated as the final step in committing your corrections to disk by generating a new set of media files. The Render Queue lets you render some or all of the shots in your project once they’ve been corrected in Color.

You can use the Render Queue to render your project either incrementally or all at once. For example, if you’re working on a high-resolution project with a multi-day or multi-week schedule, you may choose to add each scene’s shots to the Render Queue as they’re approved, preparing them for an overnight render at the end of each day’s session. This distributes the workload over many days and eliminates the need for a single time-consuming render session to output the entire program at once.

The Graphics Card You’re Using Affects the Rendered Output

Color uses the GPU of the graphics card that’s installed in your computer to render the color correction and geometry adjustments that you’ve applied to the shots in your program. Different video cards have GPU processors with differing capabilities, so it’s entirely possible for the same Color project to look slightly different when rendered on computers with different graphics cards. To ensure color accuracy, it’s best to render your project on a computer using the same graphics card that was used when color correcting that program.

Which Effects Does Color Render?

Projects that are imported from XML and EDL project files may have many more effects than Color is capable of processing. These include transitions, geometric transformations, superimpositions, and speed effects. When rendering your finished program, your import/export workflow determines which effects Color renders.

In particular, if you render out 2K or 4K DPX or Cineon image sequences to be printed to film, Color renders the shots in your project very differently than if you’ve rendered QuickTime files to be sent in a return trip back to Final Cut Pro.

In all cases, the corrections you’ve made using the Primary In, Secondary, Color FX, and Primary Out rooms are always rendered.

Effects That Aren’t Rendered in a Color–to–Final Cut Pro Roundtrip
  • When you shepherd a project through an XML-based Final Cut Pro–to–Color roundtrip, all transitions, filters, still images, generators, speed effects, Motion tab keyframes and superimposition settings, and other non-Color-compatible effects from the original Final Cut Pro project are preserved within your Color project, even if those effects aren’t visible.

  • Color Corrector 3-way filters are the exception. The last Color Corrector 3-way filter applied to any clip is converted into a Primary In correction in Color. When you send the project back to Final Cut Pro, all Color Corrector 3-way filters will have been removed from your project.

  • When you’ve finished grading your program in Color and you render that project as a series of QuickTime movies in preparation for returning to Final Cut Pro, any of the previously mentioned effects that have been invisibly preserved are not rendered. Instead, when you send the finished Color project back to Final Cut Pro, such effects reappear in the resulting Final Cut Pro sequence. At that point you have the option of making further adjustments and rendering the Final Cut Pro project prior to outputting it to tape or as a QuickTime master movie file.

Effects That Are Only Rendered for 2K and 4K Output
  • When rendering out DPX or Cineon image sequences, all clips are rendered at the resolution specified by the Resolution Presets pop-up menu in the Project Settings tab of the Setup Room.

  • When rendering out DPX or Cineon image sequences, all the transformations you made in the Geometry room’s Pan & Scan tab are rendered.

  • When rendering out DPX or Cineon image sequences, all video transitions are rendered as linear dissolves when you use the Gather Rendered Media command to consolidate the finally rendered frames of your project in preparation for film output. This feature is only available for projects that use DPX and Cineon image sequence media or RED QuickTime media, and is intended only to support film out workflows. Only dissolves are rendered; any other type of transition (such as a wipe or iris) will be rendered as a dissolve instead.

  • Effects that you need to manually create that aren’t rendered by Color include any video transitions that aren’t dissolves, speed effects, composites, and titles. These must be created in another application such as Shake.

Effects That Are Rendered When Projects Use 4K Native RED QuickTime Media
  • When rendering projects using 4K native RED QuickTime media, the output is always rendered at the resolution specified by the Resolution Presets pop-up menu in the Project Settings tab of the Setup room. Additionally, all the transformations you’ve made in the Geometry room’s Pan & Scan tab are always rendered into the final media. This is not true of projects using 2K native RED QuickTime media.

  • If you’re outputting to film and you’ve set the Render File Type pop-up menu in the Project Settings tab of the Setup room to DPX or Cineon, then all video transitions are rendered as linear dissolves when you use the Gather Rendered Media command to consolidate the finally rendered frames of your project in preparation for film output. This feature is only available for projects that use DPX and Cineon image sequence media or RED QuickTime media, and is intended only to support film out workflows. Only dissolves are rendered; any other type of transition (such as a wipe or iris) will be rendered as a dissolve instead.

  • If you’re sending the project back to Final Cut Pro and the Render File Type pop-up menu in the Project Settings tab of the Setup room is set to QuickTime, effects such as transitions that have been invisibly preserved are not rendered. Instead, when you send the finished Color project back to Final Cut Pro, such effects reappear in the resulting Final Cut Pro sequence. At that point, you have the option of making further adjustments and rendering the Final Cut Pro project prior to outputting it to tape or as a QuickTime master movie file.

Motion Settings, Keyframes, and Pan & Scan Adjustments in Roundtrips

A subset of the static motion settings from Final Cut Pro is translated into the equivalent Pan & Scan settings in Color when you first import the project. These settings have a visible effect on your Color project and can be further adjusted as you fine-tune the program. However, if you’re rendering QuickTime output in preparation for sending your project back to Final Cut Pro, these effects are not rendered by Color unless your project uses 4K native RED QuickTime media; ordinarily, static Pan & Scan settings are passed from Color back to Final Cut Pro for rendering there. Keyframes are handled differently:

  • Keyframed Scale, Rotation, Center, and Aspect Ratio Motion tab parameters from Final Cut Pro do not appear and are not editable in Color, but these keyframes are preserved and reappear when you send your project back to Final Cut Pro.

  • Color Pan & Scan keyframes cannot be translated into corresponding motion effect keyframes in Final Cut Pro. All Color keyframes are removed when you send your project back to Final Cut Pro, with the settings at the first frame of each clip being used for translation.

For more information, see Exchanging Geometry Settings with Final Cut Pro.

Some Media Formats Require Rendering to a Different Format

There are many codecs that Color supports for media import, such as the XDCAM, MPEG IMX, and HDV families of codecs, that cannot be used as the export format when rendering out of Color. Most of these are formats which, because they’re so highly compressed, would be unsuitable for mastering. Additionally, many of these formats use “squeezed” anamorphic frame sizes, rather than the standard full-raster SD and HD frame sizes that programs are typically mastered to. For all of these codecs, two things happen when you render media for output:

  • Media formats that are unsupported for output will be rendered using a different codec: If the media in your project uses a codec that’s not supported for output, then every shot in your project will be rendered using a different codec that is supported. In these cases, Color supports a specific group of codecs that are either lightly or completely uncompressed that are suitable for mastering. You can choose which of these codecs to render your media with by choosing from the Resolution and Codec Settings controls in the Project Settings tab of the Setup room.
  • Media formats that are rendered using a different codec will be rendered full raster: If you’re rendering using a different codec, all anamorphic media in your project will be resized to the closest full-raster frame size. For example, media using the anamorphic 1280 x 1080 or 1440 x 1080 frame sizes will be rendered using the standard 1920 x 1080 frame size.

Whenever rendering your project changes the codec, frame size, or both, you are presented with a dialog when you send your project to Final Cut Pro that asks: “Change graded Final Cut Pro sequence to match the QuickTime export codec?”

  • If you click Yes to change the sequence settings to match the graded media rendered by Color, then the codec used by the sequence sent to Final Cut Pro will be changed from the one that was originally sent to Color. Also, the frame size of the sequence will change to match the frame size of the rendered media.

  • If you click No, the settings of the sequence that Color sends back to Final Cut Pro will be identical to those of the sequence that was originally sent from Final Cut Pro to Color, but the codec used by the clips won’t match that of the sequence, and the rendered clips will have their scale and aspect ratio altered to fit the original frame size.

For a complete list of which codecs are supported by Color, see Compatible QuickTime Codecs for Import.

For a list of the mastering codecs that Color supports for output, see Compatible QuickTime Codecs for Output.

Rendering Mixed Format Sequences

If you edit together a mixed format sequence in Final Cut Pro—for example, combining standard definition and high definition clips of differing formats—you can still send it to Color, as long as each clip of media throughout the sequence is in a format that’s compatible with Color.

When you render the finished project, how the final media is processed depends on the format you’re rendering to:

  • If you’re rendering QuickTime media to send back to Final Cut Pro: Each shot is individually rendered with the same frame size, aspect ratio, and interlacing as the original media file it’s linked to. Regardless of the project’s resolution preset, standard definition shots are rendered as standard definition, high definition shots are rendered as high definition, progressive frame shots are rendered progressive, and interlaced shots are rendered interlaced. On the other hand, every shot in the project is rendered using the QuickTime export codec that’s specified in the Project Settings tab of the Setup room, and if the original frame size is a nonstandard high definition frame size, then it is changed to the nearest full-raster frame size when rendered.

    When you send the project back to Final Cut Pro, the Position, Scale, Aspect Ratio, and Rotation parameters of each shot in the Pan & Scan tab of the Geometry room are passed back to each clip’s corresponding Motion tab settings in Final Cut Pro, so that all of the clips conform to the sequence settings as they did before. However, each rendered media file in the project that was sent back to Final Cut Pro should have the same frame size, aspect ratio, and interlacing as the original media files that were originally sent to Color.

    If the original frame size of the sequence was a nonstandard high definition frame size, then you have the option of either changing the sequence frame size when you send the project back to Final Cut Pro to match that of the full-raster media rendered by Color, or leaving it alone. In either case, the Motion tab settings for each clip in Final Cut Pro are automatically adjusted so that all clips fit into the returned sequence in the same was as they did in in Color.

    Ultimately, it’s up to Final Cut Pro to transform and render all clips that don’t match the current sequence settings as necessary to output the program to whichever format you require.

  • If you’re rendering 4K native RED QuickTime media, or DPX or Cineon image sequences to be output by a film printer: In this case, all shots are rendered according to the Position, Scale, Aspect Ratio, and Rotation settings in the Pan & Scan tab settings, with the final frame size conforming to the currently specified resolution preset. The final result is a series of DPX or Cineon image sequences with uniform frame sizes.

Mixing Frame Rates is Not Recommended

Mixed format sequences are extremely convenient during the offline edit of a project that incorporates a wide variety of source material. For example, it’s extremely common to mix high definition and standard definition clips in documentary programs. In many cases, you can mix formats with different frame sizes and finish your program using the original media without problems.

However, it’s not recommended to send a sequence to Color that mixes clips with different frame rates, particularly when mixing 23.98 fps and 29.97 fps media. The resulting graded media rendered by Color may have incorrect timecode and in or out points that are off by a frame.

Furthermore, when outputting to tape, all sequences should consist of clips with matching frame rates and field handling (progressive or interlaced) for the highest quality results.

If you have one or more clips in your sequence with a frame rate or field handling standard that don’t match those of the sequence, you can use Compressor to do a standards conversion of the mismatched clips. For more information, see Final Cut Studio Workflows, available at http://documentation.apple.com/en/finalcutstudio/workflows.

Rendering Projects That Use Multiclips

If you’re working on a project that was edited using the multicamera editing features in Final Cut Pro, the multiclips in your sequence need no special preparation for use in Color. (They can be sent to Color either collapsed or uncollapsed.) However, no matter how many angles a multiclip may have had in Final Cut Pro, once a sequence is sent to Color, only the active angle for each multiclip is visible for grading and rendering. The resulting sequence of rendered media that is sent back to Final Cut Pro consists of ordinary clips.