6.0 KiB
LTX Video Prompting — Quick Reference
Condensed from the 544-line deep research at /home/n8n/workspace/general/LTX_prompt_instructions.md.
Prompt Order (Official LTX 2.3)
LTX Studio's pipelines weight tokens by position. Two orderings work well:
Order one (shot-size-first): framing → subject → action → style → motion Use when the shot size is the most important decision. "Wide shot, low angle, a detective in a long coat walks toward a warehouse door, harsh sodium lighting, slow push-in."
Order two (subject-first): subject → action → framing → style → motion Use when the character or object is more critical. "A woman in a red coat walks through a Tokyo street at night, medium tracking shot, neon reflections in puddles, handheld follow."
Failure mode: piling every adjective into one long noun phrase. Cut to the 2-3 that matter most.
For I2V specifically: Focus the prompt on motion and action — the visual starting point is already defined by the input image. Avoid describing static elements already visible in the image. Describe the transition from stillness to motion.
Source: ltx.io/blog/ltx-2-3-prompt-guide, ltx.io/blog/how-to-write-a-prompt (official, June 2026)
Shot Sizes
| Shot | What It Shows |
|---|---|
| Extreme Wide | Vast environment, subject tiny |
| Wide / Establishing | Full body + surroundings |
| Medium Wide | Knees up |
| Medium Shot | Waist up |
| Medium Close-up | Chest up |
| Close-up | Face and neck |
| Extreme Close-up | Single feature |
Camera Angles
| Angle | Effect |
|---|---|
| Eye Level | Neutral, familiar |
| Low Angle | Power, dominance |
| High Angle | Vulnerability |
| Bird's Eye | Detached, god-like |
| Dutch Angle | Unease, tension |
| Over-the-Shoulder | Dialogue |
| POV | First-person immersion |
Camera Movements
| Movement | Prompt Phrase |
|---|---|
| Static | "Static camera," "tripod-locked" |
| Dolly-in | "Slow dolly-in," "camera pushes forward" |
| Dolly-out | "Camera pulls back slowly" |
| Pan | "Slow pan left/right" |
| Tilt | "Tilts up to reveal" |
| Tracking | "Tracks alongside," "follows behind" |
| Orbit | "Camera orbits slowly around" |
| Handheld | "Subtle handheld, micro-shakes only" |
Lighting
| Type | Prompt Phrase |
|---|---|
| Window light | "Soft north-window light, gentle falloff" |
| Golden hour | "Golden hour rim light, long shadows" |
| Overcast | "Overcast, diffuse light, low contrast" |
| Tungsten | "Practical lamp as key, warm tungsten" |
| Neon | "Neon glow, cyan and magenta reflections" |
| Backlight | "Backlit rim light, subject silhouetted" |
| High contrast | "High-contrast studio lighting, deep shadows" |
Lens Cues
- "35mm lens, f/2.8, shallow depth of field" — people/products
- "85mm portrait lens, bokeh, crisp eyes" — talking heads
- "16mm wide, deep focus" — rooms/landscapes
- "50mm standard" — natural perspective
Motion Verbs
Walking, pouring, turning, lifting, revealing, drifting, sprinting, reaching, pausing, stepping, rising, falling, swaying, flickering, rotating, gliding, accelerating, decelerating, spinning, floating, sliding, bouncing, nodding, shaking, gesturing, breathing, blinking, smiling, frowning, gasping, laughing, crying, whispering, shouting
Emotion — Show, Don't Tell
❌ "A sad woman sits at a table" ✅ "A woman sits at a table, her shoulders slumped forward, eyes downcast, fingers tracing the rim of an empty coffee cup"
Negative Prompt
no extra limbs, no face warp, no object duplication
no text artifacts, no floating logos, no watermark
no extreme motion blur, no rolling shutter wobble
no flicker, no frame-to-frame texture shift
no Dutch angle, no rapid handheld, keep horizon level
For I2V: add static, frozen, no motion, Ken Burns zoom
Transition LoRA (zhuanchang)
- Use ONLY on transition/morph scenes — character morph, style change, scene switch, day→night
- NEVER on standard I2V — the LoRA forces transformation behavior even without the trigger word. Confirmed 2026-07-21: caused subject duplication and wrong-scene hallucination on standard I2V scenes.
- Place at END of prompt
- CFG: 4.0 (not 1.0 — Transition LoRA needs higher CFG)
- Strength: 1.0
- Node: LoraLoaderModelOnly (standard ComfyUI node, NOT LTX2LoraLoaderAdvanced)
guide_strength (RESOLVED 2026-07-22)
Use 1.0 for all standard I2V with ID LoRA dropped. The old "1.0 = NEVER" rule was from v4 where ID LoRA was also at 1.0 — the duplication was stacked LoRA interference, not guide_strength alone. With ID LoRA dropped, 1.0 is clean and provides proper start-frame anchoring.
| Value | When | Why |
|---|---|---|
| 1.0 | Standard I2V (no ID LoRA) | Proper start-frame anchoring. Confirmed clean in 2-clip test. |
| 0.5-0.7 | I2V WITH ID LoRA (talking-head only) | Lower strength prevents LoRA interference |
Verify after render:
ffprobe -v quiet -show_entries format_tags=prompt output.mp4 | grep -oP 'guide_strength.*?(\d+\.?\d*)'
Common Mistakes
| Mistake | Symptom | Fix |
|---|---|---|
| guide_strength too low (0.5) | Identity drift, weak start-frame anchoring | 1.0 (safe with ID LoRA dropped) |
| ID LoRA on action scenes | Frontal-face bias, fights camera motion | Drop ID LoRA entirely |
| Transition LoRA on standard I2V | Wrong scene, hallucinated content | Remove Transition LoRA entirely |
| zhuanchang on every scene | Model forces morphing everywhere | Only on actual transitions |
| No camera direction | Static/random movement | Add dolly/pan/tracking |
| Prompts too short (<30 words) | Model fills gaps with random data | 50-80 words minimum |
| No motion detail | Character freezes | Sequential action in present tense |
| Emotional labels | Abstract expressions | Physical cues only |
| Conflicting descriptions | Averaged competing signals | One speed, one camera, one light |
| euler_ancestral_cfg_pp on fp8 distilled | Catastrophic artifacts, hallucinated subjects | Plain euler only |