# Tempo Density Guide — avoid slow-motion micro-expression videos

Use this guide when a subtle acting prompt feels too slow, floaty, or like slow motion. The goal is normal physical speed with dense, readable micro-beats.

## Source pattern observed from creator prompt examples

A strong acting prompt often uses:

- explicit time ranges;
- normal-speed verbs such as 快速、短促、不到半秒、立刻、重新、继续;
- emotion beats tied to visible physiology: gaze, blink, brow, lower eyelid, lip shape, jaw, breath, throat, shoulder;
- sequential micro-actions instead of simultaneous stacked descriptions;
- precise degree limits: 动作不能夸张、不要立刻流泪、不要大幅动作;
- audio or line rhythm when dialogue exists;
- gaze continuity: look at target → briefly look away → force gaze back.

## Key rule

For 5–7 second micro-expression videos, do not stretch one expression change across the entire clip. Use 4–7 small beats at normal speed.

Bad:

- “慢慢眨眼，缓慢呼吸，逐渐恢复。”
- “镜头极慢推进，表情慢慢变化。”
- one vague emotion held for 7 seconds.

Good:

- “0.0–1.0s 保持基线；1.0–1.6s 眨眼晚半拍；1.6–2.4s 眼神短暂失焦；2.4–3.2s 下颌轻收并吞咽；3.2–4.5s 吸气恢复；4.5–6.0s 视线重新聚焦。”

## Recommended timing density

### 5 seconds

- 0.0–0.8s baseline
- 0.8–1.5s first leak
- 1.5–2.4s recovery attempt
- 2.4–3.5s second leak or breath beat
- 3.5–5.0s after-state

### 6–7 seconds

- 0.0–1.0s baseline
- 1.0–1.7s delayed blink or gaze shift
- 1.7–2.6s brow/mouth/jaw micro-change
- 2.6–3.5s swallow or breath catch
- 3.5–4.6s recovery / suppression
- 4.6–6.5s after-state, visually changed but not frozen

### 8–10 seconds

Use 6–9 beats. Add one small head/shoulder/hand beat if supported by the source image. Avoid filling the duration with slow camera drift.

## Verb choices that preserve normal speed

Prefer:

- 短促地
- 半拍后
- 不到半秒
- 立刻压回
- 快速恢复
- 轻轻一顿
- 重新聚焦
- 呼吸漏拍
- 晚半拍眨眼
- 下颌短暂收紧

Avoid overusing:

- 缓慢
- 极慢
- 慢慢
- 逐渐
- 悠长
- 长时间
- 凝固
- 停住很久

Use “慢慢” only when the shot is intentionally lyrical and the user wants slow pacing.

## Single-shot timestamp format

Even for one continuous shot, timestamps are allowed. They describe performance beats, not cuts.

Template:

全程单镜头，一镜到底，不切镜，不换景别，不转场。以下时间段均发生在同一个连续特写镜头内：

- 0.0–1.0s: baseline...
- 1.0–1.7s: first leak...
- 1.7–2.6s: facial/breath detail...
- 2.6–3.5s: interruption or swallow...
- 3.5–4.6s: recovery...
- 4.6–6.5s: after-state...

## Micro-expression density checklist

Before video generation, check:

- Does the prompt have at least 4 timed beats for a 5–7s clip?
- Did I avoid turning every beat into “slowly”?
- Are the verbs normal-speed and physiologically plausible?
- Are the changes sequential, not all at once?
- Is the camera continuity locked as single-shot if required?
- Is the final emotional polarity protected?