Where do black bars come from?
The black areas along the top and bottom of a video, also known as letterboxing, have become synonymous with the signature look and feel of big-screen movies viewed at home. Letterboxing occurs when films shot in a wide aspect ratio get resized to fit standard-width video players.
Most movies are filmed in a 2.35:1 or 21:9 ultrawide aspect ratio, also known as CinemaScope or anamorphic. While movie theaters are equipped to show these wide aspect ratios without letterboxing, that’s often not the case for screens like your TV, laptop, or cell phone.
If a film with a wider aspect ratio is shown on a screen with different dimensions, the video player will automatically reduce the size of the content so that the widest edges fit in the frame, and add black bars to fill in the empty space. This mismatch between your screen and the movie’s native aspect ratio is what’s responsible for the black bars that are associated with a cinematic look.
Use an ultra widescreen aspect ratio to get black bars.
To get the letterbox look without cropping any video footage, use a cinematic aspect ratio when you film.
You can also crop your footage to different aspect ratios in the video editing phase in order to achieve this look with tools like Auto Reframe in Adobe Premiere Pro. Check out this tutorial to learn how to use this AI-powered feature. If you go this route, be aware that you could lose some video quality due to a reduction in pixel count.
But if you shot your footage in an aspect ratio such as full screen (4:3), or widescreen (16:9), you can also add letterboxes as an overlay in post-production with a video editor app. Here’s how: