Apple Final Cut Pro 7 - Manual (Page 1465)

Choosing Real-Time Playback Gamma Correction Options
Whenever you watch your video on a computer display (such as video displayed in the
Canvas, the Viewer, or via Digital Cinema Desktop Preview), Final Cut Pro applies gamma
correction to the video to more closely approximate the way it would appear on a video
monitor.
Note: Gamma correction is not applied to external video outputs such as DV or third-party
interfaces because this correction is inherently applied by external video monitors.
If your computer’s graphics card supports gamma correction, Final Cut Pro automatically
uses the card for accurate gamma correction. If your computer has an older graphics card
that does not support gamma correction, you have two gamma correction options in the
Playback Control tab of the System Settings window.
• Accurate: High-quality gamma correction. This option is the most accurate but also
requires the most processing power.
• Approximate: Lower-quality gamma correction. This option leaves more processing
power available for real-time effects but results in less accurate color and brightness
rendition.
Tip: If your real-time performance is limited, try changing the gamma correction setting
to Approximate (if available).
To choose a gamma correction option in the current sequence
1 Open a sequence in the Timeline.
2 Choose Final Cut Pro > System Settings, then click the Playback Control tab.
3 Choose Accurate or Approximate from the Gamma Correction pop-up menu.
Changing Gamma Settings for Video and Imported Still Images
When you import certain video or still-image formats, Final Cut Pro attempts to determine
what gamma correction has already been applied to the media and stores that value in
the clip’s Gamma Level property. During playback, Final Cut Pro uses the Gamma Level
property to determine whether a clip requires gamma correction.
In general, Final Cut Pro assumes the following:
• Most RGB-encoded media (such as TIFF or the Apple Animation codec) has an implicit
gamma of 1.8. This assumption is correct for images created on a Mac computer with
display profile gamma set to 1.8. If the image file was created on a different platform,
or on a Mac computer with display profile gamma set to 2.2, you may need to adjust
the clip’s Gamma Level property to 2.2.
Because the Apple ProRes 4444 codec has been designed to work with Final Cut Pro
and has a native gamma of 2.2, it automatically eliminates potential gamma shifts.
• Y
′
C
B
C
R
media has an implicit gamma of 2.2. You cannot adjust the gamma of Y
′
C
B
C
R
clips.
1465 Chapter 85 Rendering and Video Processing Settings