位深Bit Depth

位深（也叫色深）是每个颜色通道被量化成多少级台阶——8bit 每通道 256 级，10bit 1024 级，12bit 4096 级。

• 幅度那一维的采样：把连续的明暗切成台阶（见 采样），位深就是台阶数。
• 台阶不够的后果：渐变不再平滑，出现一圈一圈的色带——天空和暗部最显眼。
• 8bit 够看、10bit 才够调：调色要反复推拉数值，10bit 起步才不容易拉出断层。
• AI 生成素材：按 8bit 标，位深是五维图上它的短板之一（约 0.22）。

Bit depth (also color depth) is how many quantisation steps each color channel gets — 8bit is 256 steps per channel, 10bit 1024, 12bit 4096.

• The amplitude dimension of sampling: continuous light cut into steps (see Sampling); bit depth is the step count.
• Too few steps: gradients stop being smooth and band into rings — skies and shadows show it first.
• 8bit to watch, 10bit to grade: grading pushes and pulls values; below 10bit the breaks show quickly.
• AI-generated footage: tagged 8bit — bit depth (about 0.22) is one of its sunken vertices on the five-axis chart.