Why Do Some Releases Of Older Movies Have Black Borders?

by Justin Sevakis,

Duc asked:

Every once in a while, especially when I'm watching an older movie on Blu-ray, I'll see a thin border around the picture. Why is that there? Also, can you explain the difference between pillarboxing and letterboxing?

Sure. When we talk about black borders on video, we could be talking about multiple things. First, we have letterboxing (only on the top and bottom) and pillarboxing (only on the sides). Those are added when the native shape, or aspect ratio, of a movie or TV show doesn't match the final presentation format. For example, an old TV show, which was made for 4x3 TVs, needs to have pillarboxing added when it's released on Blu-ray, because Blu-ray can only be in widescreen. The black is spacing, and is added to fill out the screen. The original shape of the picture is preserved, and no part of the image is cut off (ideally).

There are times when the letterboxing and pictureboxing collide, such as when you play an old letterboxed widescreen DVD (encoded as 4x3) on a modern HDTV. The TV will sense a 4x3 signal and add black borders on the sides, unaware that there already IS a black border on the top and bottom of the picture. The resulting image now has a giant black border all around it, and the picture is now a tiny inset in the middle of the screen. (You should be able to zoom it in on most TVs, though.) A similar issue happened with the new Viz DVDs of Sailor Moon, which still had the black pillarboxing on the sides added to make a widescreen HD master, and was put on the disc as a widescreen image. Old 4x3 TVs thought it was a widescreen image and added letterboxing on top of it. Viz has stated that they won't be doing that on future releases.

But what I think you're talking about is what happened on older Bandai Visual transfers: a thin black box is added around the entire perimeter of a new HD master, even though it's unnecessary. The reason for this is something called "overscan," and it's a relic of how old tube TVs used to work.

A tube display, hard as it is to believe, is actually an electron gun. From the back of the display, the gun shoots electrons at a layer of phosphorous on the inside of the front of the screen, and those electrons cause the phosphorous to glow for a fraction of a second. But those electron guns weren't all that accurate back in the day, and to fill the screen, TV manufacturers set the guns to slightly overshoot the size of the screen. Exactly how much they overshot depended on variances in voltage the TV was getting from the power outlet, and in the video signal. The broadcast industry compensated for this by coming up with an area of the screen they determined "action safe" and an area they determined to be "title safe." Anything within "Action Safe" is something you could count on not getting cut off on the vast majority of TVs. "Title Safe" is even further inside, since the edges of the screens would often warp the image a bit. All text had to be displayed within Title Safe.

This is the safe area for a widescreen display. The outer rectangle is the "Action Safe" perimeter, while the inner rectangle is "Title Safe."

None of this has been necessary for a very long time. Modern LCD displays do not natively cut off anything, and even tube displays, toward the end of their run, didn't really need to either. But the industry had started hiding stuff like closed captioning data in the hidden areas of the picture, so the practice stuck. While the vast majority of TVs sold today will show you the entire picture, many of them default to zooming in the image a little bit, on broadcast TV if nothing else. (If you zoom out on broadcast TV, you can see a thin line of static on top, which is where the closed caption data is.) Some cheap TVs won't let you turn off the zooming at all. Early tube HDTVs were especially bad about that. So, when Bandai Visual created new HD masters of a good number of its classic films, they added a thin black box to the outside. You know, just so everyone could see the entire image.

As far as I know, only Bandai Visual did this. While it might have seemed like a good idea at the time, nowadays you look at those HD transfers and go, "what the hell, why is there a black box here?" Needless to say BV doesn't do that anymore, but in the mean time, many of the crown jewels of the company's back catalog still have transfers with these black bars.

Occasionally other companies will do this just for credit sequences, if old films have titles that otherwise wouldn't be within title safety -- another standard that no longer really makes any sense, and yet is still rigidly enforced by most broadcasters.

Thank you for reading Answerman!

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Anime News Network founder Justin Sevakis wrote Answerman between July 2013 and August 2019, and had over 20 years of experience in the anime business at the time. These days, he's the owner of the video production company MediaOCD, where he produces many anime Blu-rays. You can follow him on Twitter at @worldofcrap.

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