---
title: "How to add a motion blur with Claude (tested prompt and ffmpeg command)"
description: "A second in, the orbiting shot starts to smear: the holographic backdrop, the acrylic block and the label lettering drag soft trails in the direction the camera moves, while the bottle's outline stays readable. Install one skill and ask Claude Code, or run the ffmpeg command we tested yourself."
url: https://www.recharm.com/effects/motion-blur
---

# How to add a motion blur with Claude

A second in, the orbiting shot starts to smear: the holographic backdrop, the acrylic block and the label lettering drag soft trails in the direction the camera moves, while the bottle's outline stays readable.

Made by the command on this page, from our own test clip.

## Get this effect

1. ### Switch to Code in your [Claude Desktop App](https://claude.com/download)

2. ### Install the skill (once)

   ```
   Install the Recharm video effects skill: download https://recharm-growth-staging.s3.us-east-2.amazonaws.com/website/downloads/recharm-video-effects.zip and unzip it into ~/.claude/skills
   ```

3. ### Ask for the effect

   ```
   Add a motion blur to input.mp4
   Second the blur starts fading in: 1.0
   Seconds it takes to reach full blur: 0.3
   ```

## Several videos, several effects, one ask

Put your clips in the folder, mention them with @, and ask for everything at once. Claude runs one tested script after another on each clip, then joins them.

Add a motion blur to **@clip1.mp4**, put a sale badge on **@clip2.mp4**, give **@clip3.mp4** a VHS look, then join all three with crossfades.

## Settings you can change

Ask Claude to change any of these, or edit them at the top of the command.

| Setting | Default | What it does                                                                                     |
| ------- | ------- | ------------------------------------------------------------------------------------------------ |
| `START` | `1.0`   | Second the blur starts fading in. Before it the video is untouched.                              |
| `RAMP`  | `0.3`   | Seconds it takes to reach full blur.                                                             |
| `TRAIL` | `18`    | Frames blended into each output frame. 18 at 30fps is a 0.6s shutter; more makes longer streaks. |

## Without the skill

Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the command itself.

```
In input.mp4, add motion blur that fades in from 1.0 seconds to full strength at 1.3 seconds and stays to the end; before 1.0s the video must be untouched. Make the blur by averaging each frame with the 17 frames before it (18 frames, a 0.6 second shutter at 30fps) using ffmpeg's tmix filter, weighted 1, 2, 3 ... 18 from oldest to newest so the current frame is the strongest and older positions fade out behind it as a trail. Fade it in by overlaying the blurred copy on the original with its alpha ramping from 0 to 1 between 1.0s and 1.3s. Keep the size (540x960), 30fps, 6 seconds and the audio. Use ffmpeg, encode H.264 yuv420p and save it as output.mp4.
```

## Run it without Claude

This is the exact command we tested. Save it as `motion-blur.sh` and run:

```
sh motion-blur.sh input.mp4 output.mp4
```

```
#!/bin/sh
# Motion blur: from 1s on, everything that moves smears into a soft trail behind it, like a long shutter.
# Usage: sh motion-blur.sh input.mp4 output.mp4  (needs only ffmpeg)
set -e
IN="$1"; OUT="$2"
START=1.0    # second the blur starts fading in (before it the video is untouched)
RAMP=0.3     # seconds to reach full blur
TRAIL=18     # frames blended into each output frame (18 at 30fps = a 0.6s shutter)

# each output frame averages the last TRAIL frames, newest weighted heaviest (weights 1..TRAIL),
# so the current picture stays readable and the older positions fade out behind it as a streak
WEIGHTS=$(seq -s ' ' 1 "$TRAIL")
ffmpeg -y -i "$IN" -filter_complex "\
[0:v]fps=30,format=yuv420p,split[sharp][src];\
[src]tmix=frames=$TRAIL:weights='$WEIGHTS',format=yuva420p,fade=in:st=$START:d=$RAMP:alpha=1[blur];\
[sharp][blur]overlay=format=auto,format=yuv420p[v]" \
  -map "[v]" -map 0:a -c:v libx264 -crf 18 -pix_fmt yuv420p -c:a copy "$OUT"
```

## More motion and camera

- [2.5D parallax photo **2.5D parallax photo**](https://www.recharm.com/effects/2-5d-parallax-photo)
- [Back-and-forth loop **Back-and-forth loop**](https://www.recharm.com/effects/back-and-forth-loop)
- [Background blur **Background blur**](https://www.recharm.com/effects/background-blur)
- [Bullet time **Bullet time**](https://www.recharm.com/effects/bullet-time)
- [Cinemagraph **Cinemagraph**](https://www.recharm.com/effects/cinemagraph)

## Find 3x _winning ads_

Recharm cuts your ad footage into tagged, searchable clips: hooks, testimonials, product shots. Find the shots that win, add the effect with Claude, and ship 3x more ad edits.

[Start 14-day free trial](https://www.recharm.com/get-started)