A-roll and B-roll
Adobe describes B-roll as all of the footage that is not the main action, while A-roll is the principal footage, such as a person speaking to camera (Adobe). In a product review, A-roll is the reviewer talking. B-roll is the product being unboxed, the buttons being pressed and the screen up close.
Why editors use it
- To show what the speaker is describing instead of only telling.
- To hide jump cuts where a sentence has been trimmed.
- To change the picture every few seconds, which keeps short-form viewers watching.
- To set the scene with an establishing shot of a place.
Shooting B-roll for a client
Make a shot list before the shoot: the product from three angles, hands using it, the shop front, customers (with permission) and a few slow detail shots. Film more than you think you need. For a café in Islamabad or a clothing brand in Faisalabad, twenty minutes of good B-roll can supply a month of reels.