Green screen work is the one creator task where most of the brief is technical, and where a clip that looks fine to the person filming can be unusable to the person compositing.
What to put in the public brief
- That a plain, evenly lit backdrop is required
- The wardrobe restriction, stated plainly
- Clip length and whether they speak
- That the raw file is the deliverable, not an in-app effect
- The licence
Keep the asset they will react to private.
What to put in the private instructions
Say to stand well away from the backdrop
At least a stride. Shadow on the wall is the most common reason a clip will not key, and it is entirely a distance problem.
Name the wardrobe rule
Nothing in the backdrop colour, nothing translucent, no glasses reflecting the screen if avoidable. Say it as a rule rather than a suggestion.
Ask for even light on the backdrop and on them separately
One lamp pointed at both produces a hotspot that keys unevenly.
Ask for the unedited file, no effect applied
State it twice. This is the instruction most likely to be misread as the platform feature.
Proof worth requiring
Ask for
The raw unedited file at native resolution, plus one still with the person out of frame so you can see the empty backdrop.
Do not ask for
A pre-keyed clip with a transparent background. Amateur keying is destructive and you cannot recover the edge detail once it has been cut.
When this task type is the wrong tool
If the background does not need replacing, do not ask for this — an ordinary reaction clip is cheaper and available from far more workers.
If you need broadcast-grade compositing, the setup requirements exceed what a marketplace brief can reliably specify, and a studio is the honest answer.