Inputs
First identify what is actually unstable
Watch the clip once while ignoring the action. If the same face changes shape, hairline or age, that is identity drift. If the face stays recognizable but skin texture, jewellery, background lines or light pulses between frames, that is flicker. If the whole frame bends during a camera move, it is geometric instability. These categories need different fixes: stronger source identity for drift, fewer fine details for flicker, and simpler motion or framing for geometric warping. Calling every problem flicker leads to random prompt edits that may solve the wrong layer.
Start with the strongest source frame
Image-to-video inherits both the strengths and ambiguities of its first frame. A soft face, cropped hand, reflected profile or busy pattern gives the model several plausible ways to reconstruct the subject, and those choices can change over time. Use a sharp source at the final aspect ratio, with the subject separated from the background and important features fully visible. Do not expect motion generation to repair a weak still. If needed, generate or edit the starting frame first, approve it as an image, and only then animate it.
Remove prompt instructions that fight the image
A common image-to-video prompt repeats the full appearance description and quietly contradicts the source: a different hair length, lighting direction, wardrobe detail or camera angle. The model then alternates between what it sees and what it reads. Strip the prompt back to movement, expression and camera. If a visible attribute must change, name only that change and accept that it raises the risk of drift. Several appearance changes plus a large camera move is effectively a new generation, not an animation of the original frame.
Steps
- Classify the failure as identity drift, local texture flicker or whole-frame geometric warping.
- Replace the source with a sharp, uncropped frame at the intended output aspect ratio.
- Remove appearance descriptions that duplicate or contradict the source image.
- Lower motion amplitude and keep the face visible through one continuous action.
- Test the shortest available duration before increasing resolution or clip length.
- If two restrained attempts fail, change template or model family instead of repeating the same request.
Parameters and controls
Reduce motion before adding detail
Large head turns, fast spins, abrupt occlusion and rapid camera orbits force the model to invent views that are absent from the source. Every invented view is a chance to rebuild the face or costume differently. Lower motion amplitude, keep the face visible and replace sudden direction changes with one continuous action. If the model offers a motion-strength control, reduce it. If it does not, use observable restraint in the prompt: “slight head turn,” “gentle hair movement,” or “slow push-in, subject remains still.” Stability usually improves before any extra quality phrase is added.
Shorten the clip to locate accumulated drift
Identity errors compound over time. If the first three seconds are stable and the final two are not, the prompt may be fine and the duration is simply beyond what that shot can hold. Generate the shortest available test. When it works, extend cautiously or chain clips using a clean final frame as the next starting frame. This is cheaper and more diagnostic than repeating a long render. Resolution can improve visible detail, but it does not fix an identity that has already changed; duration and motion are the first controls to adjust.
Know when to change the template or model
A template pairs a workflow, prompt pattern and model. If the same source and restrained motion remain unstable across two attempts, switch to another template that asks for less motion or uses a different model family. Repeating the identical request only samples the same weakness again. Compare with one simple baseline template: if that holds the subject, the original effect is too ambitious for the source or model; if every model drifts, return to the starting image and prompt conflict checks before spending more credits.