Luma Uni-1 Guide

A practical guide to Luma’s Uni-1 unified model for image creation and precision editing

Uni-1 is Luma’s first unified model designed for both image creation and precision editing. Beyond raw output quality, what makes it powerful is control: you can generate entirely new images or surgically modify existing ones, while guiding the system with references, seeds, and structured prompts.

This guide gives you a working mental model and practical workflows, from your first image to advanced multi-reference setups.

What makes Uni-1 different

• Two clear modes: Create Image (generate something new) and Modify Image (edit something existing)
• Up to 9 reference images, each with a defined role
• Strong control over niche and specific visual styles
• Seed support for reproducibility and controlled iteration
• Nine aspect ratios, from ultra-tall to ultra-wide

If you understand the modes and how to control references, you understand Uni-1.

The core distinction: Create vs Modify

Everything in Uni-1 starts with one question: Am I creating something new, or changing something that already exists?

Mode	What it does	When to use
Create Image	Produces a brand-new composition. Can be inspired by references.	”Create a new scene in the style of this photo”
Modify Image	Edits a specific input image. Preserves composition and structure unless told otherwise.	”Make this photo look like nighttime”

When in doubt:

• If the output should look like a version of your input, use Modify
• If it should feel inspired but new, use Create

Your first image

1. Open Create Image > Uni-1
2. Write a prompt
3. Choose an aspect ratio
4. Generate

Example prompt:

A wide cinematic landscape during a violent storm. Rolling green hills,
a lone tree in the foreground, chaotic lighting, dramatic clouds and
atmosphere. Photorealistic.

The real workflow is simple: prompt → evaluate → refine. Leave the seed blank while exploring. Once you find something strong, lock the seed and iterate from there.

Core parameters

Parameter	Description
Prompt	Your primary control. Up to 6,000 characters. Be precise.
Aspect ratio	Controls framing, not quality. Choose based on use case.
Seed	Same seed + same prompt → same result. Same seed + changed prompt → controlled variation. No seed → exploration.
Reference images (Create)	Up to 9 images to guide different aspects.
Source image (Modify)	The image you are editing. Dimensions are preserved automatically.

Working with reference images

References only work if you tell the model what they are for. Use this structure:

Use IMAGE1 ([description]) as a [ROLE] reference.

Possible roles: Style, Character, Composition, Color palette, Lighting, Texture, Mood.

Without roles, the model guesses, and guesses are unreliable.

Create mode examples

Style reference

Use IMAGE1 (impressionist oil painting with loose brushwork and warm
sunset tones) as a STYLE reference. Create a portrait of a woman in her
30s applying IMAGE1's color palette and painterly texture. The subject
should be new.

Character reference

Use IMAGE1 (woman with short copper-red hair, freckles) as a CHARACTER
reference. Preserve her features. Generate a new scene: she's sitting
in a softly lit café.

Multi-reference

Use IMAGE1 as a COLOR PALETTE reference, IMAGE2 as LIGHTING, IMAGE3 as
COMPOSITION. Create a lone figure walking through a rain-slicked street
at night.

Modify mode examples

In Modify mode, clarity is everything. Always specify what to change and what must stay untouched.

Change the time of day to golden hour. Update sky, light direction,
shadows, and color temperature. Keep all subjects and composition
unchanged.

Make the rain heavier and add reflections on the ground. Keep all other
elements unchanged.

Prompting guidelines

Recommended lengths:

• Text-to-image → 80–250 words
• Reference-guided → 100–300 words
• Modify → 30–100 words

Avoid vague terms (“beautiful”, “amazing”), redundant phrasing, and conflicting instructions. Instead, use specific, named aesthetics:

• Golden hour, 85mm lens, shallow depth of field
• 1970s Italian giallo film poster, high-contrast color blocking

Precision beats generality.

Aspect ratios

Choose based on where the image will live:

Ratio	Use case
1:1	Social posts
9:16	Vertical video
16:9	Widescreen
3:2 / 2:3	Photography
2:1 / 3:1	Cinematic / panoramic
1:2 / 1:3	Ultra-tall

In Modify mode, aspect ratio is locked to the source image.

Seeds: control and reproducibility

Seeds turn experimentation into systems.

• Fixed seed → consistency
• No seed → exploration

Workflow:

1. Explore with no seed
2. Find a strong result
3. Lock the seed
4. Change one variable at a time

Save your prompt and seed together. That’s your reusable recipe.

Advanced techniques

Character consistency

1. Generate a clean, front-facing reference image
2. Reuse it as IMAGE1 (CHARACTER) in every scene
3. Keep the label identical across prompts

Multi-reference architecture

Assign one role per image:

• IMAGE1 → character
• IMAGE2 → style
• IMAGE3 → lighting
• IMAGE4 → environment

End the prompt with:

Treat each reference as having authority over its assigned layer only.

Create → Modify chain

Use Create to explore compositions, then Modify to refine details. This is one of the most powerful workflows.

Iterative refinement

1. Explore (no seed)
2. Lock seed
3. Change one variable per generation
4. Document results

It feels slower, but it’s actually faster, because you always know what changed.

Troubleshooting

Problem	Fix
References ignored	Label each one clearly
Modify changes too much	Explicitly state what must stay unchanged
Inconsistent outputs	Lock the seed
Prompt partially ignored	Remove conflicts or split into steps
Output looks like the reference image	You may be in Modify mode
Character inconsistency	Reuse a canonical reference image

Quick reference

Create Image

• New compositions
• Text + up to 9 references
• Descriptive prompts

Modify Image

• Edits existing images
• Source image + references
• Direct, surgical prompts

The golden rules

1. Label every reference
2. In Modify mode, always state what should not change
3. Change one variable at a time when refining
4. Save prompt + seed for reproducibility
5. Create = new scenes, Modify = edits

Key takeaway

Mastering Uni-1 comes down to three things: choose the right mode → control your references → iterate with intention. Once those are in place, you’re no longer guessing, you’re directing.