This tutorial is an original manually prepared language version. It does not use the article live-translation service.
Quick answer
Use Smart Crop when one clear face or subject should remain centered in a vertical frame. Preview or test the result whenever the source includes multiple speakers, fast movement, screen text or wide scenery.
Use the relevant BestAI tool with one short test file or paragraph first. Confirm the result, then process a larger batch. This prevents a small setting mistake from being repeated across many clips or a long narration.
Why this tutorial matters
Converting 16:9 footage to 9:16 removes a large part of the original frame. Automatic subject tracking can save time, but the visually most obvious face is not always the person who should remain on screen. Editorial context still matters.
The BestAI workflow is designed around a simple rule: one active control should own one decision. When a mode overrides another setting, the conflicting control is disabled in the interface and ignored by the backend. This makes the plan shown on screen match the actual result.
Recommended starting settings
| Setting | Practical starting point |
|---|---|
| Target frame | 9:16 for vertical Shorts and Reels. |
| Best source | One visible face with stable lighting and limited obstruction. |
| Contain mode | Use when the whole wide frame or screen recording must remain visible. |
| Multi-person scene | Prefer manual review or a wider crop. |
| Text safety | Keep captions and source text away from cropped edges. |
These values are starting points, not universal rules. Source quality, speaking style, platform, audience and the purpose of the video can require a different choice.
Step-by-step tutorial
Step 1: Identify the primary subject
Decide who or what the clip is about before selecting the crop. In an interview, the active speaker may change; in a product demo, the product may be more important than the face.
Step 2: Check source composition
Smart Crop works best when the subject is distinct from the background. Low light, side profiles, rapid cuts and partial faces can make tracking less stable.
Step 3: Choose fill or contain deliberately
Fill creates a full vertical frame but removes side content. Contain preserves the original frame with background or bars. Use contain for screen recordings, group scenes and wide landmarks when cropping would remove meaning.
Step 4: Run a representative test
Choose a segment with the most difficult movement, speaker change or camera pan. A stable opening does not prove that the entire clip will remain framed correctly.
Step 5: Protect captions and overlays
Place subtitles inside a central safe region. Check that platform buttons, the crop and any source graphics do not compete for the same space.
Step 6: Correct exceptions manually
If one segment changes subjects or loses important text, process it with a different crop setting rather than forcing one global choice on every output.
Quality-control checklist
- The intended subject remains visible throughout the test.
- Speaker changes do not leave the active person outside the frame.
- Product labels and screen text remain readable.
- Subtitles avoid platform controls and source overlays.
- Wide shots use contain or a deliberate crop when needed.
Common mistakes to avoid
- Assuming the largest face is always the correct subject.
- Applying the same crop to interviews, screen recordings and landscapes.
- Testing only the first few seconds.
- Placing subtitles directly over a tracked face.
- Ignoring rapid pans and hard cuts between different compositions.
Frequently asked questions
Does Smart Crop replace manual framing?
It reduces repetitive work, but difficult scenes still need a human check and sometimes a different crop mode.
Why does the frame jump between people?
Multiple visible faces or fast speaker changes can make the preferred target ambiguous. Use a wider crop, split the scene or process it separately.
When should I use contain mode?
Use it when preserving the complete source frame is more important than filling every pixel of the vertical canvas.
Practical example
A two-person interview begins with one speaker, switches to the guest and briefly shows both people. Smart Crop may work during individual close-ups but jump during the two-shot. Export that section with a wider crop or contain mode while keeping Smart Crop for the rest.
When automatic tracking is unsuitable
Use a different approach for screen tutorials, group discussions, sports action, wide travel scenes and footage with frequent hard cuts. Preserving the viewer's understanding matters more than maintaining a full-screen crop. ## Final takeaway
Smart Crop is strongest as a time-saving first pass for one clear subject. Test the hardest scene, protect text and captions, and use a different framing choice for exceptions.