---
title: Vertical that follows the subject, not the middle of the frame
summary: A 9:16 version of a clip with the crop following one named person the whole way through.
lede: The crop follows a named person's face, not the centre of the frame
outcome: cut
tools: reframe_person, job_wait, commit_to_library
order: 2
---

> Make a vertical version of GroundSlate clip beach-interview-9f8e7d6c at 1080x1920 with the crop following p203 (Mila) the whole way, moving with her rather than jumping between positions. Tell me how much of the clip stayed on her face and where the crop had to fall back, then file the result in project prj_0a1b2c3d4e.

- Name the person. Without that, a vertical crop is the middle of the frame and she walks out of it.
- `reframe_person` tracks her face everywhere the index saw her, smooths the path, and renders one file with the crop moving every frame. It works in a crowd, and it reports how much of the clip stayed on her and where it held or fell back to the shot's own subject.
- Faces must be indexed first; face recognition is one of the steps in the app's setup. A clip where she was never recognised is refused, with the fix named, instead of getting a bad crop.