How to film with placeholder screens and drop the real clips in later
Film your piece to camera with a plain coloured placeholder where each clip will go, then send Vizard Agent the footage and the clips. It measures the placeholder's shape in every section separately, works out a key threshold that survives your room's lighting, and fits each clip to the real geometry.
What do you type into Vizard Agent?
Say out loud that the placeholders are placeholders. Left unexplained, a green rectangle sitting in shot reads to Vizard Agent as exactly that, a green rectangle. The useful version names it as a slot, says which clip fills it, and mentions if your framing changed between takes.
Prompt
What does Vizard Agent actually do?
Filming with something physically there gets your gesture, eyeline and timing right. The edit then rests on one decision: the placeholder is measured separately in every section rather than once, because a key pulled from the first shot and applied throughout is why the second half fringes. In the session behind this article it:
- Measured the placeholder geometry in each section separately and fitted the shape, which was a disc, not a rectangle.
- Tested the key on each section individually and ran a single-frame composite test for each one.
- Simulated a colour-and-brightness key rule against the real pixels to find clean thresholds, then tested a tight key using the exact measured screen colour.
- Viewed the tight composites to confirm nothing was eaten, and fixed one section's crop where the framing had drifted.
- Assembled the cut, re-checked the inserted screens and reviewed them as a grid before delivery.
When does this not work well?
Keying is unforgiving about lighting and colour collisions, and most failures here are created at the shoot, not in the edit. A placeholder lit from one side is two colours, green in your clothing keys out with it, a reflective screen keeps its reflections, and motion blur makes the edge ambiguous. None of these can be fixed afterwards without visible cost.
Common questions
Does the placeholder have to be green? No. Vizard Agent measures whatever colour you used. Green is just convenient.
What if I moved between takes? Say so. Vizard Agent measures each section separately.
Does the clip have to be the same shape? No. Vizard Agent fits it to the measured geometry.