Apple Final Cut Pro 6 - Manual (Page 1455)

670 Part IV Real Time and Rendering
In general, Final Cut Pro assumes the following:
 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 Macintosh
computer, but if the image file was created on a different platform, you may need to
adjust the clip’s Gamma Level property to 2.2.
 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.
Supported File Formats
Final Cut Pro supports gamma adjustment for the following file formats:
 Still images: JPEG, PNG, TIFF, SGI, PlanarRGB, MacPaint, and layered or flattened
Photoshop (PSD) files.
 QuickTime movie files: Movie files using the None or Animation codec
Adjusting Gamma in Imported Still-Image and Video Clips
There are two places to adjust gamma:
 Gamma Level pop-up menu in the Editing tab of the User Preferences window:
This pop-up menu globally determines gamma at the time media is imported.
 Gamma Level clip property in the Item Properties window or Browser column: You can
adjust the gamma of individual clips in the Browser or in the Item Properties
window. This allows you to override the global setting applied by the Gamma Level
pop-up menu in the Editing tab of the User Preferences window.
A Common Gamma Correction Scenario
One of the most common situations that requires you to change the Gamma Level
property of a clip is when you are rendering an RGB clip within a Y´C
B
C
R
sequence.
Final Cut Pro uses QuickTime to import RGB media and always assumes that RGB
media has a gamma of 1.8 (technically, 1/1.8). When Final Cut Pro renders these clips
in a Y´C
B
C
R
sequence, the image is brightened by an additional 1/1.22 to match the
2.2 gamma compensation required in the sequence (Y´C
B
C
R
uses a gamma of 2.2).
The problem with this default behavior is that RGB files are not always created with a
gamma of 1.8. For example, RGB files created on platforms other than Mac OS X often
have gamma correction designed to compensate for 2.2 in the monitor. In this case,
you can adjust the gamma level of your imported RGB clips.