Skill · Video
Green-Screen Killer
Background swaps in Runway Aleph 2.0 that match the subject's light, previewed as a still first, with a checklist that catches what makes a composite look fake.
When to use
- You have footage with the wrong or a boring background and want a different one.
- You want to move a subject to a new setting (an office interview onto a rooftop).
- A composite you already made looks fake and you want to know why.
When not to use
- Hair-level, frame-accurate keying for broadcast: a keyer in a compositing app is still more precise.
- You want a new scene from scratch: use Frame-to-Film Workflow or Text to Video.
- Clips longer than 30 s: split them at cuts first, since Aleph 2.0 edits clips up to 30 s.
Example
User: 12 s interview clip, a man in an office, soft window light from camera right, warm-neutral, static camera. Replace the office with a rooftop at golden hour.
Result (abbreviated): FIT: ok - static camera, short hair, no glass. SUBJECT LIGHT: key from camera right · warm-neutral · soft · shallow depth of field · eye level, medium lens MISMATCH: full golden hour is warmer than his skin tones -> late afternoon, sun low at camera right, softer warmth. CHANGE PROMPT: "Replace the office behind him with a city rooftop in late afternoon: low sun from camera right, soft warm light, a concrete ledge and potted olive trees in the middle distance, the skyline out of focus in light haze. The man stays exactly as he is." IF IT FAILS - halo around his hair -> add "the edge of his hair blends into the soft background haze".
Illustrative example; actual output will differ.
What is inside
The full skill has these sections. The ones marked “in the pack” come with the download.
- When to use on this page
- When not to use on this page
- Inputs to ask for in the pack
- Workflow in the pack
- Rules in the pack
- Output format in the pack
- Example on this page
- Model notes (Oct 2026) in the pack
- Troubleshooting in the pack
- Paste-in version (for chats without skill support) in the pack
Get Green-Screen Killer
The full skill is a SKILL.md folder you install once and reuse: the workflow, the checklist and the answer format written out, with notes for each model. It comes in the Video pack (3 prompts · 24 skills · 1 free), with a QUICKSTART, setup notes in every item and 12 months of updates.
All-Access 39 € vs 7 packs × 12 € = 84 € · less than buying 4 or more packs one by one
Stuck? Email support@meevra.com — we'll help you set it up.