Relight a video with AI by API: pixel filters or a prompted edit

Sume has no relight tool for video. Two things get close: a pixel pass with dim, exposure and eq in the video filter, which changes brightness and tone everywhere equally, and a prompted edit through the video router, where you describe the lighting and add "Keep everything else the same." A pixel pass cannot move a light source or add shadows.

Higgsfield's changelog (Aug 21, 2026) lists Relight as a standalone tool with six presets (Silhouette, Practicals, Window, Overhead Fall, Contre-jour, Soft Cross) plus Auto, and up to two custom light sources. Sume facts are from Video filter and Video router, read 2026-10-01.

What can a pixel pass do?

The dim op multiplies luma across the whole clip: amount in (0, 1], where 0.45 is darker and 1 is unchanged. The docs say black stays black and chroma does not shift. exposure and eq are allowlisted filters for tone; their option strings are standard ffmpeg, so run POST /v1/video-filter/check before paying for an encode.

{
  "video_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4",
  "ops": [{ "op": "dim", "amount": 0.45 }],
  "filtergraph": "eq=contrast=1.15"
}

What can a prompted edit do?

A video_to_video request takes video_url and a prompt that describes the edit; the docs' example ends with "Keep everything else the same." Lighting changes belong here because the model can rewrite shading, which a global filter cannot. Results depend on the model, so review the output.

Which should I choose?

Does this work for stills too?

For a single image, see relight a photo with AI. Video filter sources are capped at 300 seconds.