What is the Difference Between A-Roll and B-Roll?

We value variety because it keeps things interesting. Without that vital spice, life can become quite bland.

But life isn’t the only thing that benefits from variety. Having read our guide to successful corporate video production, you will know that a balance of A-roll and B-roll footage provides your video with variety, helping to enhance your message and hold the viewer’s attention.

But what is the difference between A-roll and B-roll?

To answer that question, let’s go back to basics.

What is A-roll?

Variously described as main footage, primary footage or principal shots, A-roll is the part of your video that tells the story, and communicates your central message. It will feature your key plot points, and be the driving force behind the narrative.

In the realm of fiction, A-roll is Jack and Rose dancing in the depths of Titanic, Bilbo Baggins entrusting the ring to Frodo, or Joey cracking wise in Friends. In a corporate video, your A-roll footage is more likely to feature an interview with an industry specialist, the presentation of a new product, or speeches made at an awards ceremony.

But viewers are unlikely to be captivated by 12 minutes of A-roll on its own. After all, a recent study conducted by Microsoft concluded that the human attention span lasts for just eight seconds. A single, continuous shot or scene is likely to have people switching off.

That’s where B-roll footage comes in.

What is B-roll?

If A-roll tells a story, B-roll gives it context. It is everything that surrounds the main action – illustrating the core message, and enhancing your viewer’s experience.

When we watch something, our perspective is limited to what we are shown on the screen. B-roll can expand that perspective, adding details which help us to better understand the story. This might include footage of where the video is being filmed, your subject candidly carrying out a particular action, or transitional shots that illustrate the passing of time.

B-roll is great at setting the scene, but it is also the editor’s friend. Let’s say your A-roll features an interview with an industry expert. That expert might cough; they might fumble the answer to a question, requiring multiple attempts; or they might simply not answer one question as well as another. 

Editing this footage will likely require lots of cutting and stitching together, causing the subject’s posture, facial expressions and tone of voice to change suddenly. B-roll (such as footage of what your subject is talking about) can mask these transitions, making it a more pleasant and captivating experience for your viewer. 

Using TV news as an example, the presenter might be talking about a devastating storm that’s caused disruption across the UK. Suitable B-roll footage might include shots of fallen trees, trains that have derailed, and houses that have had tiles blown off their roofs. 

In another segment, perhaps about the role that location and deprivation plays in the achievement of GCSE results, viewers might be shown B-roll footage of school scenes, such as students moving from one class to another or pens busily scribbling across exam papers.

In short, B-roll footage simply enhances your core message.

It might do so by including some of the following:

• Atmospheric shots of scenery;
• Undirected footage, such as a subject candidly using machinery;
• Reenactment footage, shown while a narrator tells a story;
• Shots of your crew setting up equipment for the interview;
• Transitional shots such as time lapses; or
• Archive footage illustrating the history of an event.

How did A-roll and B-roll get their names?

To understand the etymology behind A-roll and B-roll, we need to step back in time and take a trip to the first half of the 20th century, when film footage was captured and stored as physical rolls of film rather than digital files.

During this era, editing often meant splicing two pieces of film stock together. For the narrow 16mm film popular in this era, the result was a fuzzy transition where tape had been placed over the cuts, briefly interrupting the movie. To solve this visual problem, two sets of footage (designated A-roll and B-roll) ran side by side: one with the new footage, and one with the old footage cut out.

Each reel filled the blank areas with black ‘leader’ film, which would prevent light passing through it, and would thus not be projected. When one reel reached the leader film (where a shot had been edited out), the other reel would project the new shot, preventing the messy splice from showing up on screen.

Once filmmakers began referring to primary footage as A-roll and secondary footage as B-roll, the names stuck, and stayed with video production teams as they moved through the digital revolution of the 80s and into the present-day.

Tips for shooting B-roll

The terms ‘A’ and ‘B’ rightfully imply a hierarchy. After all, your primary footage is likely to be far more important to the core message of your video than the secondary. But the pitfall many productions fall into is not treating their B-roll as an asset at all.

Here are three tips to ensure your B-roll carries almost as much value as your A-roll:

1. Incorporate movement

A steady camera is an essential part of your corporate video production, but that doesn’t mean it has to be static. B-roll event footage that moves with your arriving guests, for example, can make the viewer feel like a part of the proceedings. An aerial camera that traces the wave-lapped coastline will build drama, while a time-lapse shot that moves along a motorised slider will feel a little more dynamic than one that’s stationary.

2. Use B-roll as a visual punchline

According to the Sprout Social Index, one of the main reasons why we watch videos, aside from the story, is to laugh. It is for that very reason that 71% of social media users click on a video. But while  incorporating comedy into your corporate video can be a good idea, at some point you will need a punchline. B-roll footage can be an ideal medium for visual gags, and a way to pay off or even set up jokes.

3. Capture subjects that aren’t obviously interesting

You won’t always be surrounded by exciting subjects. That’s okay. Shooting B-roll footage of someone pouring a drink, two people chatting, a microphone being plugged in, someone tying their tie, tickets being collected, photographs being taken, and any other relatively mundane occurrences can make your corporate video feel more human, and provide important context to your A-roll.

How much A-roll versus B-roll should you shoot?

As we mentioned in our guide to corporate video production, you should aim to shoot enough B-roll to cover six times the total video length. For example, if you’re aiming to produce a two-minute video, 12 minutes of B-roll will suffice. But that rule isn’t set in stone. If your A-roll is full of variety, you may not need quite as much B-roll – but if your video centres on the delivery of a monologue, plenty of B-roll is advisable. 

You will notice that we haven’t pinned our colours to any masts when it comes to the amount of A-roll or B-roll required. That’s because it varies from project to project. The best way to ensure you have plenty of both is to plan your shots in advance, with both a rough duration and an idea of your cuts in mind.

To illustrate the difference between A-roll and B-roll a little better, let’s look at a couple of scenarios:

Scenario #1

You are interviewing an industry expert on both days of a two-day conference. That footage will form part of your A-roll. Unlike a character from The Simpsons, however, your subject is likely to wear different clothes between the two sessions – and if they do, your viewer is unlikely to miss it. 

To illustrate this, your B-roll footage might feature a timelapse of daytime moving to nighttime and back into daytime, or the conference hall filling up and emptying. This will implicitly show that it’s a two-day event, and provide a reason for the change in outfits.

Scenario #2

Your whisky distillery is located in the Outer Hebrides. The landscape’s rugged nature is reflected in the flavour of your spirit, a fact that is explained by your master distiller in your A-roll footage. 

To illustrate their words, suitable B-roll footage might include the whisky production process, someone drinking it, and plenty of aerial footage of the surrounding landscape. 

In summary, what is the difference between A-roll and B-roll?

Both A-roll and B-roll are essential components of your corporate video production. While the former tells your story and narrates the core message, the latter provides context and background, enhancing what you want to say.

A video without A-roll is without substance, whereas a video without B-roll will fail to capture the attention of your viewer, or immerse them in the story you’re telling. The presence of both can provide that added spice that makes a good corporate video great.

Broadcast Revolution hasn’t been around since the inception of these two terms, but we do have extensive experience combining both to make your corporate videos stand out from the crowd. To learn more, contact us today.