FLUX 1.1 Ultra raw mode and 4MP: what Sume image size accepts

"Raw mode" and "up to 4MP" are features of Black Forest Labs' FLUX1.1 [pro] Ultra endpoint, requested with "raw": true on /flux-pro-1.1-ultra. Sume's image catalog lists FLUX.2 ids such as black-forest-labs/flux.2-pro, and it has no raw field: you size a request with aspect_ratio, resolution or image_size.

BFL details are from its Ultra page; Sume details from Image API and Image generation, read 2026-10-01.

What does BFL's Ultra request look like?

The page says Ultra generates up to 4MP images and describes Raw mode as a less synthetic, more natural "candid photography" look, enabled with "raw": true. Its example body carries prompt, aspect_ratio ("1:1") and raw. The parameter table also lists image_prompt and image_prompt_strength for visual context.

Which size controls does Sume expose?

Which tiers a given model accepts is published per model on the catalog, so read GET /v1/images/models before assuming 4K.

What happens if I send a field Sume does not list?

A parameter the selected model does not list is rejected with 400 unsupported_parameter rather than silently dropped. So a raw flag sent to a Sume image model would fail, not quietly change style. For a natural, candid look, put it in the prompt text instead; see the FLUX.2 prompt guide.

What should I send instead?

Pick a FLUX.2 id from the catalog, set aspect_ratio and a resolution tier the model lists, and describe the photographic style in prompt. Aspect-ratio and custom-size rules are covered in image API aspect ratios and custom sizes.