Format-Adaptive Rembrandt Portrait Lighting

Turn a supplied photo into a complete, credible Rembrandt-lit studio hero portrait at a proportion suited to the source and intended use. Rembrandt chiaroscuro is the defining style; the studio conversion, framing, subject separation, and final grade exist to make that light hit with premium editorial authority.

Scope and subject fidelity

• Use the built-in image-generation editing workflow. If the source is a local file, inspect it with view_image first. Never overwrite the original.
• The subject can be one or more people, pets, or a mixed group. If no photo is supplied, ask the user to attach one; if they want only a prompt, provide it without generating an unrelated subject.
• Preserve the original subject, count, identity, expression, clothing, accessories, and visible anatomy. Preserve pose and viewpoint by default, but permit the controlled composition and posture refinements below when they make a static source feel like a credible new studio sitting. Do not mirror or radically re-pose merely to accommodate a lighting diagram.
• For people, preserve identity, apparent age, ethnicity, skin tone, facial proportions, hairstyle, hands, tattoos, jewelry, glasses, and wardrobe.
• For pets, preserve species, breed traits, coat color and markings, muzzle, eye color and shape, ear position, whiskers, collar, limbs, and tail. Do not humanize animal eyes, add makeup, alter paws, or invent a different animal.

Default: full low-key studio conversion

Unless the user explicitly asks to retain the scene, treat the request as a full Rembrandt studio conversion: replace the casual environment with a clean deep-charcoal-to-ink studio field and relight the subject around one dominant high-side key. It must feel like one exposure made in one studio, never a cut-out pasted onto black. A background swap without new subject lighting is a failure.

Build clear figure-ground separation: