--- title: "How to add spotlight focus with Claude (tested prompt and script)" description: "At one second the scene drops into near darkness while a soft-edged circle of light shrinks onto the bottle and stays there. Install one skill and ask Claude Code, or run the Python script we tested yourself." url: https://www.recharm.com/effects/spotlight-focus --- # How to add spotlight focus with Claude At one second the scene drops into near darkness while a soft-edged circle of light shrinks onto the bottle and stays there. Made by the script 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 spotlight focus to input.mp4 Second the spotlight starts closing in: 1.0 Seconds it takes to settle: 0.6 ``` ## 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 spotlight focus 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 script. | Setting | Default | What it does | | --------- | ----------- | ---------------------------------------------------------------- | | `START` | `1.0` | Second the spotlight starts closing in. | | `CLOSE` | `0.6` | Seconds it takes to settle. | | `X, Y` | `0.5, 0.52` | Circle center, as shares of the frame width and height. | | `RADIUS` | `0.42` | Final circle radius as a share of the frame width. | | `FEATHER` | `0.08` | Width of the soft edge as a share of the frame width. | | `DIM` | `0.22` | Brightness kept outside the circle (0 is black, 1 is untouched). | ## Without the skill Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the script itself. ``` Add a spotlight to input.mp4 with Python and numpy, using ffmpeg to read and write the frames. Before 1.0 seconds leave the video untouched. From 1.0 to 1.6 seconds (ease-out), a circle centered at 50% across and 52% down closes in from a radius of 105% of the frame width to 42% of the frame width (227 px on a 540-wide frame), while everything outside it fades to 22% of its brightness. Give the circle a soft edge 8% of the frame width wide; inside it the picture keeps its full brightness. Hold the spotlight to the end. There's no text to draw, but if you add any, draw it with Pillow, not ffmpeg's drawtext. Keep the audio and save it as output.mp4. ``` ## Run it without Claude This is the exact script we tested. Save it as `spotlight-focus.py` and run: ``` python3 spotlight-focus.py input.mp4 output.mp4 ``` ``` #!/usr/bin/env python3 """Spotlight focus: the frame goes dark except a soft-edged bright circle that closes in on the product. Usage: python3 spotlight-focus.py input.mp4 output.mp4 Needs ffmpeg and numpy (pip install numpy). """ import json import subprocess import sys import numpy as np START = 1.0 # second the spotlight starts closing in CLOSE = 0.6 # seconds it takes to settle X, Y = 0.5, 0.52 # circle center (0-1 across and down the frame) RADIUS = 0.42 # final circle radius as a share of the frame width FEATHER = 0.08 # soft edge width as a share of the frame width DIM = 0.22 # brightness kept outside the circle (0 = black, 1 = untouched) def ease_out(p): p = min(max(p, 0), 1) return 1 - (1 - p) ** 3 def light(t): """Per-pixel brightness multiplier at time t: 1 inside the circle, DIM outside.""" p = ease_out((t - START) / CLOSE) if t >= START else 0 if p == 0: return None radius = w * RADIUS * (2.5 - 1.5 * p) # starts wide and closes in on the product inside = np.clip((radius - dist) / (w * FEATHER) + 0.5, 0, 1) dim = 1 - (1 - DIM) * p # the dark fades in as the circle closes return (dim + (1 - dim) * inside)[:, :, None] def probe(path): info = json.loads(subprocess.check_output(["ffprobe", "-v", "error", "-select_streams", "v:0", "-show_entries", "stream=width,height,r_frame_rate", "-of", "json", path])) s = info["streams"][0] num, den = s["r_frame_rate"].split("/") return s["width"], s["height"], s["r_frame_rate"], float(num) / float(den) src, out = sys.argv[1:3] w, h, rate, fps = probe(src) yy, xx = np.mgrid[0:h, 0:w] dist = np.hypot(xx - w * X, yy - h * Y) reader = subprocess.Popen(["ffmpeg", "-v", "error", "-i", src, "-f", "rawvideo", "-pix_fmt", "rgb24", "-"], stdout=subprocess.PIPE) writer = subprocess.Popen(["ffmpeg", "-y", "-v", "error", "-i", src, "-f", "rawvideo", "-pix_fmt", "rgb24", "-s", f"{w}x{h}", "-r", rate, "-i", "-", "-map", "1:v", "-map", "0:a?", "-c:v", "libx264", "-crf", "18", "-pix_fmt", "yuv420p", "-c:a", "copy", "-shortest", out], stdin=subprocess.PIPE) i = 0 while True: raw = reader.stdout.read(w * h * 3) if len(raw) < w * h * 3: break img = np.frombuffer(raw, np.uint8).reshape(h, w, 3) mask = light(i / fps) writer.stdin.write(img.tobytes() if mask is None else (img * mask).astype(np.uint8).tobytes()) i += 1 writer.stdin.close() if reader.wait() or writer.wait(): sys.exit("ffmpeg failed") ``` ## More product shots - [Animated feature callouts **Animated feature callouts**](https://www.recharm.com/effects/animated-feature-callouts) - [Before/after slider **Before/after slider**](https://www.recharm.com/effects/before-after-slider) - [Best seller badge **Best seller badge**](https://www.recharm.com/effects/best-seller-badge) - [Callout arrows and circles **Callout arrows and circles**](https://www.recharm.com/effects/callout-arrows-and-circles) - [Carousel swipe **Carousel swipe**](https://www.recharm.com/effects/carousel-swipe) ## 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)