Image to image: steering instead of starting over

The studio calls it image to image, but models do two distinct things with your upload, and knowing which one you are using explains most surprising results.

• Re-render models start again from scratch, using your image as a guide. Composition and colour carry over; fine detail does not.
• Edit models treat your upload as an image to change. They aim to preserve the frame and change only what you asked for.

So to move a character into a different setting, a re-render model is the right tool. To recolour a jacket and leave the rest untouched, an edit model is. If you're not sure which you have, ask for a small change and see how much of the frame survives.

The strength control decides how far the render is allowed to travel from your reference, on a scale from just above zero to one. Re-render models respect it. Edit models decide for themselves how much to keep, so on those, moving the slider changes little or nothing.

• 0.2 to 0.4 — a pass over the original. Lighting and materials shift, structure holds.
• 0.5 to 0.7 — the usual working range. Recognisably your composition, freshly rendered.
• 0.8 and above — the reference becomes a loose suggestion. This is the default, at 0.8.

A reference image does not replace the prompt. On a re-render model the prompt describes the finished picture, not the change you want — writing only make it snowing gives the model almost nothing to work from, and it will drift.