9:16 vertical

Full-screen vertical: TikTok, Reels, Shorts, Stories.

Use when: All vertical social video and story ads.

Prompt instructions

Scene: [your subject] in [your setting]. First frame: 9:16 vertical frame, the subject centred with room above and below for captions Shot 1 (0:00 to 0:05): one continuous shot

Seedance 2.5 reads labelled blocks with timecodes.

SubjectSetting

Watch out

9:16 is the tallest ratio Nano Banana makes; for anything taller, generate the nearest ratio and crop.measured: Director Chair field notes on image prompting

Takes the most room in a feed without being full screen.

4:5 portraitPrompt

The standard horizontal frame: YouTube, websites, TV.

16:9 landscapePrompt

Sources

The first Director Chair spec, own words Checked 2026-10-13.

For agents: this card as markdown, as JSON.