恒定亮度补偿Constant Luminance Compensation

难度LEVELL3 · 高级L3 · Advanced 领域TOPIC调色

学习目标LEARNING OBJECTIVES

学完你能解释恒定亮度补偿（Constant Luminance Compensation）的机制，说出它何时帮你、何时碍事，并会用 Lum Mix 开关它。

概念说明CONCEPTS

恒定亮度补偿是 Resolve 的默认行为：单独调整 R/G/B 任一通道时，另两个通道被自动反向补偿，画面总亮度保持不变。它的开关就是一级校色面板参数条上的 Lum Mix——100 全开，0 关闭。

  • 校色不动曝光：压低 B 通道去黄时，R、G 自动回补——偏色没了，亮度纹丝不动，这正是"校色不该碰曝光"想要的结果。
  • Parade 上看得见：动一个通道，另两路波形跟着反向走——不是错觉，是补偿在工作。
  • 也有碍事的时候：逐通道精修黑白点（镜头匹配）或演示单通道原理时，补偿会让单通道操作"不听话"。
  • 开关即 Lum Mix：Lum Mix 拖到 0，补偿关闭、各通道独立；双击参数名回 100 恢复默认。

操作步骤STEPS

  1. 在调色页面选中片段，点右下角 Scopes 打开示波器并切到 Parade
  2. 在一级校色面板用 RGB 数字条单独压低 B 通道，同时盯住 Parade单独压低 B 通道
  3. 观察 R、G 两路波形被自动回补——偏色去掉，总亮度不变
  4. 把参数条上的 Lum Mix 拖到 0，重复第 2 步——这次只有 B 动，画面整体变暗关闭补偿后重复操作
  5. 实验完双击 Lum Mix 参数名复位到 100

练习PRACTICE

  1. Lum Mix 100 与 0 两种状态下分别抬 G 通道，用 Parade 记录总亮度是否变化。
  2. 开着补偿把一段偏蓝素材的 B 通道压到位，再改用 Offset 色轮向黄拖做一遍，对比两条路径的结果。

常见问题FAQ

我动一个通道，其他两个也跟着动——是 bug 吗？

不是，是刻意的默认行为：让校色不破坏曝光。确认不需要时，把 Lum Mix 调到 0 即可各通道独立，详见 Lum Mix 参数。

补偿会伤画质或改变饱和度吗？

不会。补偿只是三通道之间的此消彼长，不引入额外处理；需要逐通道精确操作时临时关掉，用完调回 100。

它和 Lum Mix 到底是什么关系？

Lum Mix 就是这个补偿的开关兼权重：100 = 补偿全效，0 = 完全关闭，中间值是过渡。理解了补偿，Lum Mix 就不再神秘。

Learning Objectives学习目标

After this card you can explain how Constant Luminance Compensation works, when it helps and when it gets in the way, and switch it with Lum Mix.

Concepts概念说明

Constant Luminance Compensation is Resolve's default behavior: adjusting any single R/G/B channel automatically compensates the other two in the opposite direction, so overall luma stays put. Its switch is the Lum Mix parameter on the strip below the Primaries palette — 100 fully on, 0 off.

  • Grade without touching exposure: pull the B channel down to kill a yellow cast and R, G refill automatically — the cast is gone, brightness hasn't moved an inch. That's exactly what "color correction shouldn't change exposure" means.
  • Visible on Parade: move one channel and the other two traces walk the other way — not an illusion, that's the compensation working.
  • Sometimes it fights you: when you trim black or white points channel by channel (shot matching), or demo single-channel mechanics, compensation makes one-channel moves "disobey".
  • The switch is Lum Mix: drag Lum Mix to 0 and compensation stops, every channel on its own; double-click the parameter name to return to the default of 100.

Steps操作步骤

  1. On the Color page, select the clip, open Scopes from the lower-right toolbar and switch to Parade
  2. In the Primaries palette, lower only the B channel with the RGB number fields while watching ParadeLowering the B channel alone
  3. Watch the R and G traces refill automatically — the cast is gone, overall luma unchanged
  4. Drag Lum Mix on the parameter strip to 0 and repeat step 2 — this time only B moves and the whole image darkensRepeating with compensation off
  5. Double-click the Lum Mix parameter name to reset it to 100 when you're done

Practice练习

  1. Raise the G channel once at Lum Mix 100 and once at 0, and record on Parade whether overall luma changes.
  2. With compensation on, pull the B channel of a blue-tinted clip into place; then redo the fix by dragging the Offset wheel toward yellow — compare the two paths.

FAQ常见问题

I move one channel and the other two follow — is that a bug?

No. It's a deliberate default that keeps grading from breaking exposure. If you genuinely need independent channels, set Lum Mix to 0 — see Lum Mix.

Does compensation hurt image quality or saturation?

No. It's just a see-saw between the three channels with no extra processing involved; switch it off temporarily for per-channel precision work, then return to 100.

What's its exact relationship to Lum Mix?

Lum Mix is the switch and weight of this compensation: 100 = full compensation, 0 = off, values in between blend. Understand the compensation and Lum Mix stops being mysterious.

深度资料：恒定亮度补偿 →Deep dive: 恒定亮度补偿 →

本卡术语Terms in this card

修剪Trim 调色页Color page 偏移Offset 饱和度Saturation 示波器Scopes 调色Grade