Detail Transfer

This one lives in the IC-Light pack but doesn't actually know or care about IC-Light - it's a general-purpose "take the fine detail from image A and paste it onto image B" node. It happens to be the fix for IC-Light's single most-reported complaint: relighting a photo often shifts skin tone, softens texture, or just mangles fine detail (logos, stitching, label text) that you needed to survive intact. The community's own name for the workaround is frequency separation, and it's arguably the most valuable trick in the whole relighting toolkit - take lighting (the low-frequency stuff) from your generated result, and detail (high-frequency) from the untouched original.

How it works

Give it a target (the image with the lighting you want - your IC-Light output) and a source (the original with the detail you want to keep). It blurs both by blur_sigma to isolate the low-frequency component, then blends the difference back in using one of eleven standard compositing modes - the same set you'd recognize from a Photoshop layer panel. The result carries your new lighting but the original's crisp detail.

Because it's just image-in, image-out with no model involved, it's cheap, fast, and useful well outside relighting - portrait retouching, any workflow where a generation pass softened texture you want back.

The inputs and outputs that matter

• target / source (IMAGE) - target is the relit/generated result, source is the original you're pulling detail from.
• mode (default add) - the blend mode; also available: multiply, screen, overlay, soft_light, hard_light, color_dodge, color_burn, difference, exclusion, divide.
• blur_sigma (default 1, range 0.1–100) - how aggressively to blur before separating frequencies. This is the knob that decides what counts as "detail."
• blend_factor (default 1, range −10 to 10) - strength of the transfer; negative values are legal if you want the inverse effect.
• Optional mask - restrict the transfer to part of the image (e.g. just the product, leaving the new background untouched).

Output is a single IMAGE, ready to save or feed into another compositing step.

How to install it

Via ComfyUI Manager: search "IC-light", install, restart. Manually: cd ComfyUI/custom_nodes && git clone https://github.com/kijai/ComfyUI-IC-Light, restart. No extra models to download for this node specifically - it's pure image math, no weights required.

Common issues & troubleshooting

Result looks like a harsh sharpen filter, not a detail transfer. blur_sigma is set too low - you're separating almost nothing as "low frequency," so nearly the whole image counts as detail and gets crunched back in at full strength. Push it up.

Barely any effect. Either blend_factor is too low, or blur_sigma is too high and you've blurred away the detail you were trying to preserve along with the lighting. Adjust one at a time so you can tell which is doing what.

Blend mode picking feels arbitrary. It kind of is - this is trial and error, same as picking a Photoshop blend mode. add (the default) is a reasonable starting point; overlay tends to punch contrast harder; soft_light is gentler if add looks too aggressive.

Detail bleeding into areas you didn't want touched. Wire in a mask - without one, the transfer applies across the whole frame, which is a problem if your relight changed the background on purpose and you don't want the original background's detail dragged back over it.

Where this fits in a real pipeline: the standard product-photography chain is cutout the subject, relight it (IC-Light), then run DetailTransfer with the pre-relight original as source so labels, stitching, and fine texture survive the trip. That's the whole reason this node ships inside an IC-Light pack instead of a general utilities one.