Social clips from a single photo

A social clip made from a photograph is a small promise: one picture, one movement, a caption someone can read with the sound off. It is not a trailer. The feeds that reward it are impatient, and the models that make it are only reliable for a few seconds.

Start from the frame, not the effect

Crop the photograph to the shape you will post before you upload it. For a phone feed that is tall, 9:16. Runway’s Gen-4.5 help page lists that ratio for image-to-video, along with square and widescreen. If you generate in widescreen and crop afterwards, you will cut off the subject you meant to keep.

Use a picture of one subject. A group is a still, posted as a still, perhaps with a slow zoom done in an editor rather than a generator. Generators pull extra faces in odd directions. Your friends will notice their own face first.

You also need the subject’s permission if they are a private person and the post is public. A customer, a child, or a stranger in the background is not a prop. If you would not want the still shared, do not make it move and share that instead.

The motion to ask for

Keep the prompt dull. The animation guide has a pattern you can copy: camera, what moves, what stays still. For social, “what stays still” is usually the face or the product. “What moves” is background, cloth, steam, light.

Open Runway if you want the published free credit pot and a documented image-to-video model, and check that the model is actually available on your plan. Gen-4.5 needs a paid plan on Runway’s help page. Open Luma AI if you are already on a paid plan and want a cheap 360p draft before a sharper render. Open CapCut if the “clip” is really three photos and a caption, which does not need a generator at all, or if you want to add the words after a generator has done the motion.

Sound off, words on

Most people will see the clip muted. Put the point in type, in the editor, in the middle of the frame. Edges of a phone video get covered by buttons and by the account name. If the only copy of the joke is in those edges, the joke is not there.

Do not ask the video model to render the words. Add them in CapCut or whichever editor you already use. Check the spelling at the size the phone will show, not at the size on a monitor.

Music inside a platform’s editor is often licensed only inside that platform. If the same file will also go on your website, pick music you can use in both places, or use none. A two-second whoosh is not why anyone follows you.

A test you can do today

1. Choose one photograph you are allowed to publish.
2. Write a single-sentence motion prompt with a “face stays still” or “product stays the same” line.
3. Generate two to four seconds at the cheapest setting.
4. Watch it muted, at phone size.
5. If the subject changes, stop. Post the still, or try less motion. Do not pay for a longer version of a broken take.
6. Add one line of type and export the vertical file.

That is a complete post. A second clip tomorrow, from a different photograph, will teach you more than an afternoon of rerolling the same face.

If the account is for a shop or a listing, read the product and property page before you publish. A social crop does not relax the rule about showing the thing you actually sell.