Apple Final Cut Pro 6 - Manual (Page 1312)

Chapter 26 Measuring and Setting Video Levels 527
III
Luma/Chroma Mode Pop-Up Menu
Choose one of the presets in this pop-up menu to decide the maximum allowable
chroma saturation. The normal setting of 120 should work in most situations; however,
more conservative settings are available.
Note: The number in the preset refers to the value of the combined luma and chroma
signals, mostly weighted toward the luma signal.
If you choose Custom from the Luma/Chroma Mode pop-up menu, you can use the
sliders in the Custom Luminance Limiting and Custom Saturation Limiting areas to
manually fine-tune clamping of luma and chroma levels. If any mode other than
Custom is chosen, the Custom Luminance Limiting and Custom Saturation Limiting
sliders have no effect.
Custom Luminance Limiting Controls
 Enable: Select or deselect the checkbox to enable or disable the Custom Luminance
Limiting controls.
Note: The sliders below have an effect only when this checkbox is selected.
 Clamp Above: All luma values above this parameter value are clamped to the
parameter value. The lower you set this value, the more clipping occurs at the top of
the waveform.
 Max. Output: Compresses the range of values between the Start (Threshold) and
Clamp Above values so the maximum output value is the value set here. Setting this
value higher than the Clamp Above value has no effect. Values below the Start
(Threshold) value clip the signal.
 Start (Threshold): Defines the lowest value affected by the Custom Luminance
Limiting controls.
Options in the Luma/
Chroma Mode pop-up
menu