How editors use it
In a documentary, a subject says "we lost the harvest in 2019" and the editor cuts to dry fields while the voice continues. That shot is B-roll. It also hides edits. If the editor removes a stumble from the middle of an interview answer, a jump cut would be visible on the face, so a shot of the subject's hands or the room covers the join.
On scripted work the term is looser. People use it for establishing shots, inserts of a phone screen, a clock on the wall, or a car pulling into a driveway. Much of that is shot by a second unit or at the end of a day as a pickup list.
Planning it instead of hoping for it
The worst B-roll is the stuff shot in the last twenty minutes of a day because someone remembered they needed it. Build a list during prep. For an interview-driven piece, go through the questions and write down what the audience could see during each answer.
A sample line on a documentary shot list:
| Shot | Description | Location | Notes |
|---|---|---|---|
| 14B | Maria unlocks bakery door, pre-dawn | EXT. BAKERY - NIGHT | Wide and tight, record nat sound |
| 14C | Flour sifting, macro | INT. BAKERY - KITCHEN | 60 fps for slow motion option |
| 14D | Street wakes up, delivery vans | EXT. MAIN STREET - DAWN | Tripod, 30 seconds minimum per shot |
Holding each shot for at least ten to fifteen seconds gives the editor room to choose an in and out point. A shot that wobbles for four seconds and then pans away is hard to use.
Mistakes that cost you in the edit
Crews often shoot B-roll without matching the look of the interviews, so the color and frame rate don't match and the color grading session spends time correcting it. Another problem is forgetting releases. Recognizable people and private property in B-roll still need a location release or talent release when the footage goes into a distributed film.
B-roll also inflates the shooting ratio. On documentaries it is often the largest share of the footage, which matters when you estimate drives and assistant editor time. Keep it logged by subject and location so the editor can find the bakery door at 2am instead of scrubbing through every card from that week.