When it comes to basic video terms, “A-Roll” and “B-roll” are among the ones to learn first. While it’s possibly the easiest and most fundamental distinction you’ll ever make, there is a big difference between how each one functions in video production.
A-Roll and B-Roll are terms from the old days of linear film editing, when editors would use two rolls of identical footage — an actual A-Roll and a B-Roll — to create transitions between shots. With modern non-linear editing tools, there’s no longer a need for two separate rolls, but the terms are still used today — albeit with different meanings. Now, you’ll often hear these terms used in journalistic filmmaking, as in the case of documentaries and news stories.
A great way to think of A-Roll is media that “tells” the story, such as an interview or a news segment. It’s the primary audio and video that often consists of one or more people discussing a topic or relating a narrative. A-Roll is the driving media in most documentaries, news broadcasts, talk shows, and reality shows.
The clip below is a good example of A-Roll media. The anchor’s monologue drives the story from beginning to end, while he talks about the importance of having a mobile website.
Television anchor clip by mjwolfe77
With the A-Roll alone, the story is communicated clearly. The problem is that A-Roll by itself tends to become extremely boring, making it harder for the audience to remain engaged. Remember, the audience is watching the video because they expect to have the story shown to them, not just told.
Another problem with using the A-Roll media alone is that since A-Roll footage is usually of people talking, there are often fumbled lines, coughs, sniffles, and stutters that need to be edited out. That’s where B-Roll comes in.
B-Roll is supplemental footage used to visually support the A-Roll. Think of it as video that “shows” the story. If the A-Roll narrative talks about residences, then the B-Roll might show a house. It just needs to complement, and if possible, confirm the story told by the A-Roll media. Using B-Roll footage helps break up the monotony of a common A-Roll interview shot, making the whole thing much more engaging.
B-Roll is also used as a “cutaway.” Cutaways give an editor the opportunity to remove parts of the A-Roll undetected. In the same way, an editor may use a quick cutaway to combine two portions of the A-Roll. Since the audio from the A-Roll usually acts a as a voiceover on top of the B-Roll footage, the editor can then cut out or edit parts of the A-Roll audio as needed. Cutaways are perfect for when you would like to remove a portion of an interview, or when an interviewee sputters, coughs, or says “um” too often.
The term “B-Roll” tends to make the supportive footage seem secondary and less important, but it certainly isn’t. Without the supporting footage showing the action, all you have is an interview. The B-Roll footage is really what makes a story come alive.
For the news segment A-Roll, we would probably want to capture B-Roll footage of people using their phones and tablets to access mobile websites, a few customer interactions, and a business transaction. Then we could use those shots to help the anchor show the story in a more visually engaging way.
Whatever B-Roll footage you choose to use, make sure each shot supports the narrative being driven by the A-Roll media.
Using editing software, A-Roll and B-Roll media can be mixed and merged to tell a much more engaging story. In this example, we have our B-Roll shown playing over the A-Roll. It starts with the news anchor in the studio delivering his news segment. Then, while the anchor’s audio continues to tell the story, the B-Roll footage is cut in to help support what he’s talking about.
Although this is just a basic example, you can see how A-Roll and B-Roll are used together to not just tell, but show a story. If you’ve ever filmed an interview and used supporting-action footage to supplement it, then you’ve already used A-Roll and B-Roll together properly. When you do, you tell a better story, and telling a better story is what it’s all about in the end.
Check out all of the clips that were used in this post in the A-Roll + B-Roll collection below: