BilboX post-processing vignette effect

A vignette - corners gently darker than the center - is one of the oldest cheap realism tricks in photography. It focuses the eye on the subject and, on AI output, quietly kills the perfectly flat, evenly lit look that screams "generated." BilboX post-processing vignette effect is exactly that, in node form: two sliders, one wire, no models. It's a fixed-up and improved version of the vignette from EllangoK's post-processing-nodes pack, so if you've used that one you know the shape of it.

How it works

The math is simple, which is the right call for a finishing node. It measures each pixel's distance from the image center, normalizes it, and multiplies the image by a darkening factor that falls off as that distance grows. Two sliders control everything.

• size (0–10, default 0) sets how wide the falloff is. Higher values spread the darkening over a larger, gentler radius; low values pin it tight to the corners. And here's the detail everyone misses: size 0 means the node is off - it passes the image through untouched. It ships at 0, so nothing changes until you want it to.
• opacity (0–1, default 1) is how strong the darkening is. 1 is a full-strength dark corner; drop it to 0.4–0.6 for a subtle look that survives on bright backgrounds.

The inputs and outputs that matter

Three inputs, one output. image takes any IMAGE tensor; size and opacity are the two sliders above. Output is IMAGE, which you wire into a Preview or Save Image. The natural spot in a workflow is right after the VAE decode - and ideally after your color grade, so the darkening sits on top of the grade rather than under it. Chain it after the pack's LUT node and you have a two-step finishing pass.

Install

Install it like any custom node pack. With ComfyUI Manager, search for BilboX's ComfyUI Custom Nodes (or just "BilboX") and hit Install. The manual route is the same as any other pack:

cd ComfyUI/custom_nodes
git clone https://github.com/syllebra/bilbox-comfyui

then restart ComfyUI. The pack pulls its own Python deps from requirements.txt on first load - numpy, imageio, opencv, and the heavy one, colour-science - so the first launch takes a moment. No model files, no downloads. Worth one line: the pack also adds a right-click Reboot menu that can lock or shut down the host machine. Fine on a local box; don't expose an unauthenticated ComfyUI to the internet.

Practical take

Keep opacity under 1 for portraits, or you'll get obvious dark smudges over skin tones and lose the subtlety that makes it read as a lens property. This isn't a full lens simulation - it's a radial falloff, nothing fancy - but it costs one wire and two sliders, and on landscape and street scenes it does a surprising amount of work for that cost. If you only remember one thing: leave size at 0 until you actually want the effect, because that's the off switch.