Jewelry macro in one take: Seedance 2.5 prompt, length and price

Jewelry is a small object with reflective surfaces, so keep the clip short and the motion single: one slow rotation or one slow pull-back under one light. On Seedance 2.5, an 8-second 1080p 1:1 clip costs $11.38 on Sume, and a 5-second 720p draft costs $2.89.

Long clips are the wrong tool here. The Seedance 2.5 ceiling of 30 seconds is for routes and scenes; a ring does not need it.

The macro prompt

Describe the object, the light and the motion; leave out any story.

• Object: "A thin gold ring with a small round diamond, resting on dark slate."
• Lens: "Macro close-up, very shallow depth of field, the stone sharp, the band softly blurred."
• Light: "One soft white light from the upper left, small glints on the facets, no flicker."
• Motion: "The ring turns very slowly clockwise on a turntable, a quarter turn in total."
• End: "Hold on the stone for the last second."

Pick the length by the motion

A quarter turn does not need 15 seconds. Time the motion, then pick the clip length.

Why 1:1

Square suits a product grid and the feed formats many shops use, and the Video Router docs list 1:1 among the Seedance 2.5 aspect ratios. The price does not change with aspect ratio at the same length and resolution, so you can render 1:1, 4:5-style crops later or 9:16 without a price difference. Check the model row for the exact ratio list before you send a less common one; Sume rejects values the model does not list.

The checks for this category are different from other clips. Look at the stone and the metal edge for shimmer, and at the band for a changing thickness between frames. If the metal looks plastic, say "polished gold, mirror finish" or "brushed gold, matte" in the prompt; surface words steer the look more than adjectives like luxurious.

Request

A square 8-second 1080p request. For the draft, change resolution to 480p.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: ring-macro-001" \
  -d '{"model":"seedance-2.5","prompt":"Macro close-up of a thin gold ring with a small round diamond on dark slate, very shallow depth of field. One soft white light from the upper left. The ring turns very slowly clockwise, a quarter turn. Hold on the stone for the last second.","duration":8,"resolution":"1080p","aspect_ratio":"1:1"}'

Real product, real photos

If you sell the actual ring, send your product photo as a first frame. A generated ring from a text prompt is a different ring, and a buyer will notice. The honest use of a text-only prompt is a mood clip: a setting, a hand, a light, with the real product added in your editor.

Budget three drafts and one final: $17.56 for an 8-second clip, using 480p drafts at $2.06 each.

What to expect at each resolution

Watch the end of the clip as closely as the start. A slow rotation can drift toward the end of an 8-second take, and a hold that was asked for in the last second may arrive early or late. If the stone is out of focus in the hold, shorten the rotation in the prompt rather than lengthening the clip.

Small bright highlights are the first thing to suffer at low resolution. A 480p draft is for judging motion and composition, not sparkle. If the stone looks dull at 480p, that does not tell you it will look dull at 1080p. Judge the glint pattern on the 1080p keeper only.

The reverse also holds: a 1080p clip can hide a bad rotation under good detail. So do both checks, in order: motion at 480p, detail at 1080p.

A 5-second 1080p clip is $7.11, and a 12-second one is $17.06. For a product grid loop, 5-8 seconds is enough; longer clips mostly add cost.