# Light Leak — effect skill for transitions

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A warm wash of orange/red light drifts across and blows out the frame at the cut, then fades on B.

- **Type:** [Effect](https://varg.ai/how-to/effects.md) · [Transitions](https://varg.ai/how-to/browse/skills/transitions.md)
- **Slug:** `light-leak`
- **Status:** live
- **Publisher:** HeyGen (community)
- **License:** Apache-2.0
- **Source:** https://github.com/heygen-com/hyperframes/tree/main/registry/blocks/light-leak
- **Works in:** Claude Code, Claude.ai, Codex, Cursor, OpenClaw, Gemini CLI, Any MCP client, varg Studio
- **Requires:** ffmpeg, HyperFrames (npx hyperframes), Remotion, CapCut (by hand)
- **Cost:** Free — the take renders locally; generated footage, if any, bills by the model

## What it does

Built on [Light Leak](https://github.com/heygen-com/hyperframes/tree/main/registry/blocks/light-leak) by HeyGen (HyperFrames), Apache-2.0. The write-up and recipes below are varg's.

Soft, organic colour flares (like film exposed to light) cover the cut and recede.

**When:** Memories, travel, weddings, retro or film-look edits, warm brand stories.

**Watch out:** Cold, clinical or tech content; leaks that are visibly shaped blobs.

**Timing:** 0.7–1.2 s (CapCut Light Leaks 1.0 s)

**Also called:** Light Leaks, Camera Glow, Light Beam, light leak transition, analog leak

### In FFmpeg

Overlay a light-leak clip (stock or generated) in screen mode over a short crossfade:
```bash
ffmpeg -i a.mp4 -i b.mp4 -i leak.mp4 -filter_complex \
"[0:v]fps=30,settb=AVTB,format=yuv420p[a];[1:v]fps=30,settb=AVTB,format=yuv420p[b];\
 [a][b]xfade=transition=fade:duration=0.4:offset=4.6[x];\
 [2:v]fps=30,settb=AVTB,format=yuv420p,scale=1280:720,setpts=PTS-STARTPTS+4.2/TB[l];\
 [x][l]blend=all_mode=screen:shortest=0:eof_action=pass[v]" -map "[v]" out.mp4
```
(`blend` needs equal sizes and formats; a 1 s leak clip on black starts at 4.2 s.)

### In HyperFrames

Shader `light-leak` from `@hyperframes/shader-transitions` placed at the cut (t = 4 s):
```html
<div id="s1" class="scene" style="background:#0a0a0a"><video src="a.mp4" muted playsinline></video></div>
<div id="s2" class="scene" style="background:#0a0a0a"><video src="b.mp4" muted playsinline></video></div>
<script src="https://cdn.jsdelivr.net/npm/@hyperframes/shader-transitions/dist/index.global.js"></script>
<script>
  const tl = HyperShader.init({ bgColor: "#0a0a0a", scenes: ["s1", "s2"],
    transitions: [{ time: 4, shader: "light-leak", duration: 0.7 }] });
  window.__timelines = window.__timelines || {}; window.__timelines["main"] = tl;
</script>
```
Each `.scene` needs an explicit background-color equal to `bgColor`. Or install the ready block: `npx hyperframes add light-leak`. CSS overlay: `organic-light-leak-overlay`.

### In Remotion

Light leak on the cut without shortening the timeline:
```tsx
import {lightLeak} from '@remotion/effects/light-leak';
<TransitionSeries.Overlay durationInFrames={30}>
  <Solid width={1920} height={1080} effects={[lightLeak({seed: 3, hueShift: 0, progress: interpolate(useCurrentFrame(), [0, 30], [0, 1])})]} />
</TransitionSeries.Overlay>
```
(`<LightLeak>` from `@remotion/light-leaks` is deprecated in favour of this effect; it reveals in the first half of progress and retracts in the second.)

### In CapCut

Transitions tab → Light Effect → Light Leaks, Camera Glow, Light Beam. Desktop: drag the tile onto the cut between two clips and set Duration in the right panel ("Apply to all" reuses it on every cut). Mobile: tap the small white square between clips, pick the transition, drag the duration slider, tap ✓. Tab labels and placement change between versions and regions.

### Ready-made components

- [Light Leak](https://skills.varg.ai/component/hf.light-leak/) (hyperframes): npx hyperframes add light-leak
- [Organic Light Leak Overlay](https://skills.varg.ai/component/hf.organic-light-leak-overlay/) (hyperframes): npx hyperframes add organic-light-leak-overlay
- [Light Leak](https://skills.varg.ai/component/remocn.light-leak/) (remocn): npx shadcn@latest add @remocn/light-leak
- [Light Transitions](https://skills.varg.ai/component/hf.transitions-light/) (hyperframes): npx hyperframes add transitions-light

### Where this comes from

- [Remotion: lightLeak() effect](https://www.remotion.dev/docs/effects/light-leak)
- [Remotion: <TransitionSeries>](https://www.remotion.dev/docs/transitions/transitionseries)
- [HyperFrames: @hyperframes/shader-transitions](https://hyperframes.heygen.com/packages/shader-transitions)
- [CapCut Help: transitions](https://www.capcut.com/help/transitions-in-capcut)
- [CapCut: transition categories](https://capcut.com/resource/add-video-transition-online)
- [CapCut transition names + default durations (VectCut metadata)](https://github.com/sun-guannan/VectCutAPI/blob/main/pyJianYingDraft/metadata/capcut_transition_meta.py)
- [CapCut transition names incl. Pro (pyCapCut metadata)](https://github.com/GuanYixuan/pyCapCut/blob/main/pycapcut/metadata/transition_meta.py)

## Use when

- Memories, travel, weddings, retro or film-look edits, warm brand stories.

## Not for

- Cold, clinical or tech content; leaks that are visibly shaped blobs.

## Install

- Claude Code: `claude plugin marketplace add vargHQ/skills && claude plugin install varg@varg`
- Codex: `npx skills add vargHQ/skills --skill varg-video-edit-library -a codex -y`
- Cursor: `npx skills add vargHQ/skills --skill varg-video-edit-library -a cursor -y`

## Example output

https://s3.varg.ai/how-to/previews/ac46538b4fe9/take-light-leak.mp4 — light-leak between two shots, with the timeline strip of the edit. Footage: Cosmos Laundromat (2015), (CC) Blender Foundation | gooseberry.blender.org, CC BY 4.0; Spring (2019), Andy Goralczyk / Blender Foundation (Blender Studio) | studio.blender.org, CC BY 4.0. (credit: Rendered by varg · Cosmos Laundromat (2015) + Spring (2019))

## More transitions skills

- [editly](https://varg.ai/how-to/skills/editly.md): Declarative JSON5 video editing CLI/API: clips, titles, transitions, audio mixing, rendered with ffmpeg.
- [Mix (Cross Dissolve)](https://varg.ai/how-to/skills/mix-dissolve.md): The two shots blend through each other. The quietest transition: "time passes" or "this continues".
- [Dip to Black](https://varg.ai/how-to/skills/black-fade.md): A fades to black, then B fades up. Marks the end of a section or a bigger jump in time.
- [White Flash](https://varg.ai/how-to/skills/white-flash.md): The frame blows out to white for a moment and opens on the next shot. Energy, memory or a camera snap.
- [Pull In (Zoom In)](https://varg.ai/how-to/skills/pull-in-zoom.md): The camera rushes into shot A and lands, still moving forward, in shot B. The signature short-form transition.
- [Pull Out (Zoom Out)](https://varg.ai/how-to/skills/pull-out-zoom.md): The camera jerks backwards out of shot A and keeps pulling back as shot B settles in.

## Run the generation on varg

varg is one API key for the models these skills drive — Seedance 2.5, Kling 4, Veo 3.1, Wan 3, Nano Banana 2.1, GPT Image 2.5, ElevenLabs v4 and 200+ more — billed in credits, with a cost estimate before anything runs.

- Claude Code: `claude plugin marketplace add vargHQ/skills && claude plugin install varg@varg` (skill + hosted MCP)
- Codex, Cursor, Gemini CLI, OpenClaw: `npx skills add vargHQ/skills --skill varg-ai -a <agent> -y`
- Grok and any agent that reads SKILL.md: `npx skills add vargHQ/skills --skill varg-ai`, or point it at the skill's SKILL.md
- Claude.ai, ChatGPT, any MCP client: connect `https://mcp.varg.ai/mcp`
- API key: https://varg.ai/dashboard/api · Model specs: https://varg.ai/models/llms.txt