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Table Of Contents
- Color User Manual
- Contents
- Color Documentation and Resources
- Color Correction Basics
- Color Correction Workflows
- Using the Color Interface
- Importing and Managing Projects and Media
- Creating and Opening Projects
- Saving Projects and Archives
- Moving Projects Between FinalCutPro and Color
- Reconforming Projects
- Importing EDLs
- Exporting EDLs
- Relinking QuickTime Media
- Importing Media Directly into The Timeline
- Compatible Media Formats
- Converting Cineon and DPX Image Sequences to QuickTime
- Importing Color Corrections
- Exporting JPEG Images
- Setup
- Monitoring
- Timeline Playback, Navigation, and Editing
- Video Scopes
- Primary In
- Secondaries
- Color FX
- Primary Out
- Managing Corrections and Grades
- The Difference Between Corrections and Grades
- Saving and Using Corrections and Grades
- Applying Saved Corrections and Grades to Shots
- Managing Grades in the Timeline
- Using the “Copy to” Buttons in the Primary Rooms
- Using the Copy Grade and Paste Grade Memory Banks
- Setting a Beauty Grade in the Timeline
- Disabling All Grades
- Managing Grades in the Shots Browser
- Using the Primary, Secondary, and Color FX Rooms Together to Manage Each Shot’s Corrections
- Keyframing
- Geometry
- Still Store
- Render Queue
- Calibrating Your Monitor
- Keyboard Shortcuts
- Setting Up a Control Surface
- Index
Chapter 1 Color Correction Basics 25
Chroma Subsampling
In Y´C
B
C
R
encoded video, the color channels are typically sampled at a lower ratio than
the luma channel. Because the human eye is more sensitive to differences in brightness
than in color, this has been used as a way of reducing the video bandwidth (or data
rate) requirements without perceptible loss to the image.
The sampling ratio between the Y´, C
B
, and C
R
channels is notated as a three value ratio.
Common chroma subsampling ratios are:
 4:4:4 chroma subsampled video encodes completely uncompressed color, the
highest quality possible, as the color difference channels are sampled at the same
rate as the luma channel. 4:4:4 subsampled image data is typically obtained via
telecine or datacine to a video mastering or image sequence format capable of
containing it. RGB encoded images are always 4:4:4.
Few video acquisition formats are capable of recording 4:4:4 video, but those that do
include HDCAM SR and certain digital cinema cameras, including the Thompson
Viper FilmStream camera and the Genesis digital camera system.
 4:2:2 is a chroma subsampling ratio typical for high-quality video formats, including
Beta SP, Digital Betacam, Beta SX, IMX, DVCPRO 50, DVCPRO HD, and HDCAM.
 4:1:1 is typical for consumer and prosumer video formats including DVCPRO 25
(NTSC and PAL), DV and DVCam (NTSC).
 4:2:0 is another consumer-oriented subsampling rate, used by DV and DVCAM (PAL),
HDV, XDCAM HD, and MPEG-2.
Note: As their names imply, Apple Uncompressed 8-bit 4:2:2, Apple Uncompressed 10-
bit 4:2:2, Apple ProRes 422 (SQ), and Apple ProRes 422 (HQ) all use 4:2:2 chroma
subsampling.
It’s important to be aware of the advantages of higher chroma subsampling ratios in
the color correction process. Whenever you’re in a position to specify the transfer
format with which a project will be finished, make sure you ask for the highest quality
format your system can handle (for more information about high quality finishing
codecs, see “A Tape-Based Workflow” on page 40).
As you can probably guess, more color information is better when doing color
correction. For example, when you make large contrast adjustments to 4:1:1 or 4:2:0
subsampled video, film grain or video noise in the image becomes exaggerated. This
happens most often with underexposed footage. You’ll find that you can make the
same or greater adjustments to 4:2:2 subsampled video, and the resulting image will
have much less grain and noise. Greater contrast with less noise provides for a richer
image overall.