The Apple TV’s Siri remote has a nifty feature that allows you to switch between letterbox and full-screen mode.
Modern high definition TV displays have a whole number aspect ratio of 16 wide by 9 high. That’s 1.78:1. Most (ultra) high definition TV shows that you watch on cable/satellite/streaming are mastered in that ratio as well. The content matches the physical aspect ratio of the TV display perfectly.
However, theatrical movies, even before the high definition era, have been “filmed” with aspect ratios ranging from 1.85:1 to 2.39:1 — or higher. The popular aspect ratios have changed over time, but this is a common range today. For example, Star Wars: The Last Jedi was released at 2.39:1. The Martian, shown above, was released at 2.35:1.
If you want to know a movie’s aspect ratio, you can usually find out by looking it up in the International Movie Database, imdb.com, under the Technical Specs section.
To be quite brief, when a high-aspect ratio movie is displayed on your HDTV or UHDTV whose physical aspect ratio is 1.78:1, the movie’s narrower image must necessarily have a black border above and below in order to preserve its original aspect ratio. This is called letterboxing.
By the way, modern TVs of any kind (and older Plasmas), do not suffer from the persistence of these black bars over the short period of a two hour movie. However, if they annoy you, this tip will help.
Apple TV 4th Gen and 4K
There is an interesting feature of the latest Apple TVs. I don’t know when it was introduced because the Apple TV User Guide doesn’t discuss it. But theTMO team confirmed this function on both an Apple TV 4th Gen and an Apple TV 4K, both running tvOS 11.3. I believe it also existed in tvOS 11.2.x,
Basically, if you’re watching letterboxed content, you can toggle back and forth between letterbox mode and full-screen mode with a light double tap on the Siri remote’s glass touch sensitive area. This is is not a press-click, but a light, quick, double tap.
1. This functionality has been tested and works with letterboxed movies from iTunes and the Amazon Prime app. Hulu was not tested.
2. This feature does not work with the tvOS Netflix app. I asked Netflix about that. My rep quickly responded:
This is supported functionality on our iOS app, but not yet tvOS.
The not yet phrasing gives me hope that it will be supported in the Netflix app at some future date.
3. This feature should not be confused with the Apple TV’s accessibility option called “Zoom.”
Finally, I’ve seen all too many posts on various forums in which users complain about accidentally dropping out of letterbox mode, not knowing what caused it and not knowing how to get it back. A light double tap could be triggered by fumble fingering the remote while doing something else. I would hope that Apple, someday, figures out how to solve that UI issue.