Apple Compressor 3 - Manual (Page 259)

Gamma Correction
Controls the overall brightness of an image as displayed on a monitor by changing the
gamma amount of the media file. This filter can be used to remove detail from an
underexposed clip or reduce an overexposed clip’s saturation to an acceptable level
without washing out the image too much. Computers using different operating systems
have different monitor settings. For cross-platform viewing, correcting the gamma will
improve the image for all platforms.
• Gamma: Sets a gamma setting between 0.1 and 4.0.
Letterbox
Scales and positions the image in the frame within horizontal letterbox bars.
• Type: This pop-up menu allows you to choose the type of letterboxing to use. Scale
vertically compresses the video to fit within the letterbox bars. Matte crops off the
video where the letterbox bars are placed.
• Position: This pop-up menu allows you to choose the position of the video. Center
places letterbox bars above and below the video, keeping the video centered. Bottom
positions the video at the bottom of the screen with a single letterbox bar above it.
Top positions the video at the top of the screen with a single letterbox bar below it.
• Output: This pop-up menu allows you to choose the specific aspect ratio to use for the
letterbox. Each setting is followed by a value that shows the ratio of the width to the
height for that setting. For example, the Academy setting shows its aspect ratio as
1.85:1, indicating that the image’s width is 1.85 times the size of its height. The Manual
setting enables the Manual slider, which you can use to manually set the letterbox
aspect ratio.
• Manual slider: Used when Manual is selected in the Output pop-up menu. Allows you
to manually set the letterbox aspect ratio. The Manual slider has no effect when Manual
is not selected in the Output pop-up menu.
259 Chapter 22 Adding Filters to a Setting