Lum Mix 参数Lum Mix

难度LEVELL2 · 进阶L2 · Intermediate 领域TOPIC调色

先学：Prerequisites: 一级校色器进阶控件

学习目标LEARNING OBJECTIVES

学完你能说清 Lum Mix 控制的是什么、默认 100 时发生了什么，并知道什么时候需要把它调低。

概念说明CONCEPTS

Lum Mix 决定"只动亮度（Y 通道）的对比度调整"在最终画面里占多大比重——它在一级校色面板下方的参数条上，与 Contrast、Saturation、Hue 同排，默认值 100。

  • 默认 100 = 全效：YRGB 联动调整与纯 Y 调整各占一半权重，两类操作正常叠加在画面上。
  • 调到 0 = 关掉纯 Y：单独用 Y 通道（亮度条或非联动 Luma 曲线）做的对比度调整完全失效。
  • 附带一个关键行为：Lum Mix 为 100 时，单独调 R/G/B 任一通道，另两个通道会被自动补偿，保持总亮度恒定；调到 0 则各通道互不牵连。
  • Offset 不受它管：Offset 系列控制不参与 Lum Mix 的这套逻辑。

操作步骤STEPS

  1. 在调色页面选中片段，确认当前在一级校色面板（Primaries）
  2. 在面板下方参数条找到 Lum Mix——与 Contrast、Saturation 同一排找到 Lum Mix 参数
  3. 向左拖 Lum Mix 参数名，把值从 100 降到 0
  4. 分别用 RGB 数字条单独抬 R 通道，对比 Lum Mix 100 与 0 时画面亮度的变化差异对比两种取值下的通道行为
  5. 双击 Lum Mix 参数名复位到 100——日常使用保持默认

练习PRACTICE

  1. 同一段素材上，Lum Mix 100 与 0 各做一次"只抬 R 通道"，观察画面亮度是否变化。
  2. 把 Lum Mix 调到 0，用 Y 通道 Lift 条压暗画面，再调回 100，体会"纯 Y 调整"何时生效。

常见问题FAQ

Lum Mix 平时需要动吗？

基本不动。默认 100 适合绝大多数调色；只有需要"通道互不影响"的场景——比如逐通道精确匹配、对接 CDL 流程——才临时调到 0。

为什么我动单个通道，画面没有跟着变亮？

默认 Lum Mix 100 时，其他两个通道被自动反向补偿，总亮度保持恒定——这是特性不是 bug，原理详见 恒定亮度补偿。

Lum Mix 到底在界面哪里？

一级校色面板下方的参数条上，和 Contrast、Saturation、Hue 同一排；Color Wheels、Bars、Log 三种面板模式共享这条参数区。

Learning Objectives学习目标

After this card you can explain what Lum Mix controls, what happens at the default of 100, and when you'd ever turn it down.

Concepts概念说明

Lum Mix decides how much the "luma-only (Y channel) contrast adjustments" contribute to the final image — it sits on the parameter strip below the Primaries palette, in the same row as Contrast, Saturation and Hue, and defaults to 100.

  • 100 = full effect: YRGB linked adjustments and Y-only adjustments each carry half the weight, and both kinds of moves stack normally on the image.
  • 0 = Y-only switched off: contrast moves made with the Y channel alone (the luma bars or the unganged Luma curve) stop affecting the image entirely.
  • One key side behavior: at Lum Mix 100, adjusting any single R/G/B channel automatically compensates the other two so overall luma stays constant; at 0, each channel moves on its own.
  • Offset ignores it: the Offset controls don't take part in the Lum Mix logic at all.

Steps操作步骤

  1. On the Color page, select the clip and make sure the Primaries palette is showing
  2. Find Lum Mix on the parameter strip below the palette — same row as Contrast and SaturationLocating the Lum Mix parameter
  3. Drag the Lum Mix parameter name to the left, bringing the value from 100 down to 0
  4. Raise only the R channel with the RGB number fields, and compare how the image brightness behaves at Lum Mix 100 versus 0Comparing channel behavior at both values
  5. Double-click the Lum Mix parameter name to reset it to 100 — keep the default for daily work

Practice练习

  1. On the same clip, raise only the R channel once at Lum Mix 100 and once at 0, and watch whether the image brightness changes.
  2. Set Lum Mix to 0, darken the image with the Y-channel Lift bar, then return to 100 — feel when "Y-only adjustments" actually take effect.

FAQ常见问题

Do I ever need to touch Lum Mix?

Hardly ever. The default of 100 fits the vast majority of grading; you only drop it to 0 temporarily when channels must not affect each other — for example per-channel precision matching or a CDL pipeline.

Why doesn't the image get brighter when I move a single channel?

At the default Lum Mix of 100, the other two channels are automatically compensated in the opposite direction, keeping overall luma constant — that's a feature, not a bug; see Constant Luminance Compensation for the mechanics.

Where is Lum Mix in the interface?

On the parameter strip below the Primaries palette, in the same row as Contrast, Saturation and Hue; the Color Wheels, Bars and Log palette modes all share this strip.

本卡术语Terms in this card

调色页Color page 调色轮Color Wheels 对比度Contrast 曲线Curves Lift（暗部）Lift 偏移Offset 饱和度Saturation 调色Grade