😼> Bloom

Bloom is the effect where bright light sources - a window, a lamp, the sun catching a lens - spill light past their own edges instead of stopping cleanly at a hard boundary. It's one of the cheapest ways to make a render feel like it came out of a camera instead of a diffusion model, and this node does it in one pass with one knob.

How it works

It's part of the small post-processing suite ALatentPlace bolted onto this pack in August 2024, alongside Blur, Sharpen, Scanlines and the rest. Bloom takes your decoded image and blows out the brightest areas into a soft glow layered back over the original - the same trick a real lens does when light overwhelms the sensor. There's nothing to configure about where it glows; it finds the bright spots itself and works from there.

The inputs and outputs that matter

• image (IMAGE) - your decoded frame. This runs after VAE Decode, on pixels, not on the latent.
• intensity (FLOAT, 0–1, step 0.01, default 0) - how strong the glow is. The default is off. Drop this node in and nothing will change until you actually raise the slider - that's not a bug, it's just the honest default.
• image out - feed it straight to Save Image or the next effect in your chain.

Start low - something like 0.1–0.2 - and nudge up from there. Bloom gets ugly fast if you overdo it; the whole point is that it reads as natural, and a hazy, washed-out image is the tell that you pushed too far.

How to install it

Via ComfyUI Manager: search "yanc" or "ComfyUI_yanc" and install, then restart. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/ALatentPlace/ComfyUI_yanc

then restart ComfyUI. No extra dependencies, no models to download - this is a pixel filter, same as the rest of the post-processing suite in this pack.

Common issues & troubleshooting

"I added the node and nothing changed." Check the intensity slider first. It defaults to 0, which is a genuine no-op - this is the most likely reason Bloom looks like it's doing nothing.

You want the glow confined to one part of the image. This node has no mask input, unlike its siblings Blur, Brightness, Contrast, Saturation and Sharpen in the same pack, all of which take an optional mask_opt. Bloom applies globally. If you only want the effect on, say, a window or a light fixture, run it on the full image and composite the result back over the original with a mask using ComfyUI's own ImageCompositeMasked - or generate a mask first with this pack's own Light Source Mask node and use it for the composite.

Highlights are already blown out and bloom makes it worse. If your base generation already has hard-clipped white highlights, bloom on top of that tends to look like a smear rather than a glow. It reads best on an image that still has some detail in the brights - pull exposure back slightly first if that's the case.