16:9 on a 21:9 Screen

Vizio is introducing ultra-widescreen LCD TVs with an aspect ratio of 21:9. I believe their screen sizes will be 50, 58 and 71 inches. Can you provide the formula that reveals how large a 16:9 unaltered picture will be on such a screen? I’ve read elsewhere that a 50-inch ultrawide would produce an unaltered 46-inch 16:9 image, but I have no idea how 46 inches was arrived at.

Carl King

Keep in mind that the screen size of virtually all TVs—no matter what their aspect ratio—is measured diagonally so manufacturers can specify the largest possible number. Unfortunately, this makes the math a bit tricky. Using the Pythagorean Theorem (the square of the hypotenuse of a right triangle is equal to the sum of the squares of the other two sides), and knowing that the width of a 16:9 image is three quarters the width of a Vizio ultrawide set with the same height, I calculate that the diagonal measurement of a 16:9 image is about 0.8 times the diagonal measurement of the ultrawide screen. Thus, on a 50-inch ultrawide, an undistorted 16:9 image will measure only 40 inches diagonally.

This is akin to the transition from 4:3 to 16:9, when people had to buy a much larger HDTV than they thought in order to get a 4:3 image of the same size as their old square TV. So when going from 4:3 to 16:9 or from 16:9 to 21:9, get the largest screen size you can afford that will fit into the available space.

BTW, calling these ultrawide sets 21:9 is slightly misleading. 21:9 is equivalent to 2.33:1, but the Vizios' pixel array is 2560x1080, which translates to 2.37:1.

If you have an A/V question, please send it to askscottwilkinson@gmail.com.

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Scott Wilkinson's picture
This is a good debate to be having. What is the link to this thread on AVS?

Cameron did shoot Avatar in 16:9, and the theatrical release included 16:9 and 2.35:1 (cropped), depending on the theater. And Imax is around 1.4:1 with a huge screen that fills the entire field of view, both horizontally and vertically. In a related argument, theater consultant Anthony Grimani advocates "constant area" rather than "constant height" image reproduction, which means that narrower aspect ratios should be taller than wider ones. Of course, this is only practical for front projection systems with 4-way masking screens.

On the other hand, I've also heard knowledgeable people say that the human visual system is more sensitive to horizontal resolution than vertical. Also, Cameron and many other directors say they really like the compositional possibilities of 2.35:1.

BTW, "immersive" is not included at merriam-webster.com, but it is included at dictionary.reference.com, and it's included in the Oxford English Dictionary. Therefore, it's a real word in my book.

FJH's picture

Unrealistic I may be, but it all comes down to dollars and sense. Every time devs come up with a new slant on some product, it costs the consumer more dollars to keep up.It seems to be a constant cycle anymore. Where's the sense in that. Don't get me wrong. I've been hooked on high end audio/visual since I heard a pair of Advent speakers and Marantz receiver back in the mid 70's.It just seems that there is something new every time you turn around. A case in point would be the new higher rez formats which everyone is looking forward to. For all but the biggest screens, do we really need them?( there goes them dollars again) If you truly look, 1080p material on any average screen is sharper and more vivid than real life. We need refinement not new formats every year or two. Small rant over. I do agree about the human visual system. Sit in a room and look at a wall. What you really see is not a wide image. Periphial(is that spelled right) vision does not count just like the curtains in a theater don't. You know they are there but you really only see directly in front of you.

Scott Wilkinson's picture
You're entirely right that the upgrade cycle is very fast now, and there seems to be something new every time you turn around. In my view, you can thank good ol' American capitalism, which relies on unending growth. So naturally, companies will continue to make new things for consumers to buy, and that trend will continue to accelerate. It might not make common sense, but it sure does make financial sense if your goal is ever-increasing revenue.

Of course, that trend is not fueled exclusively by corporate greed; humans are innovators by nature, so as long as we're around, we will continue to think of new and better ways to do things.

javanp's picture


It is technically a CIH vs CIW debate but the immersion factor, along with others, have been "cropping" up. Some interesting opinions on there.

I like the idea of constant height--that way all ARs are equal. But the 4-way masking system could be rather pricey.

Jarod's picture

I agree. A 4:3 image stretched to 21:9 would look horrid. I wonder how many potential buyers of a 21:9 display actually understand aspect ratios and how they would appear on this set?

Jarod's picture

This would be a very cool movie HDTV! Having 2.35:1 films fill up the screen is enticing. But watching 4:3 material sure would shrink the screen. And like said before, stretching that material to fill the screen would look comical at best. But with 2.35:1 films it sure would be slick.

uavmaj0crk's picture

In response to FJH, you're entirely right. Just when you think you're up to date with audio/visual, along comes the next big thing. 3D IS the darling of Home Theater media these days, maybe because there isn't anything else in TVs to write about. Now comes 2.35:.1. That IS new, at least here. Europe has had it a couple of years, thanks to Phillips (did you notice that huge Phillips ultrawide in Westminster Cathedral this morning?). 4:3 in native format will mean we need to buy the largest possible display (Vizio's 71") in order to get the largest possible 4.3 image short of expanding. The bottom line for this buyer will be how well Vizio executes expanding a 16:9 image to 2.35:1. Since both broadcast TV & BluRay is formatted for 16:9, each of us will have to decide if Vizio did it's job according to our individual tastes.

FJH's picture

Awww gee Scott. You've gone all philosophical on me.Seriously though, I can't argue the capitolism angle. Being a conservative I do not want to speak badly towards profits(within reason). I also wanted to comment on the immersion factor. It seems to me that in a darkened room, any reasonable size of screen at the correct viewing distance should provide total involvement. It does not have to be an ultra wide.

KAPLANENT's picture

I think these cinema-wide flat panels are a great alternative to a constant height projector set-up for people that don't have the room.

The downside: As these become more popular, will we be subjected to 16:9 and 4:3 material all stretched to 21:9.

I cringe at the thought. It's bad enough now that everywhere you go (even in other countries) we have to endure 4:3 images stretched to 16:9...and almost nobody thinks anything is wrong.

FJH's picture

These wider screens are a bad idea. There is enough confusion in the audio/visual world without a new screen format. All movies and tv should be 16:9 period.No black bars, top or bottom. This is just another gimmick from Vizio to try to set their tvs apart from all the others. The buying public has been subjected to enough format changes in the industry. We need some stability.

uavmatthewweflen's picture

The thought of someone stretching a blurry 4:3 SD signal to 21:9 and calling it "high def" makes me positively vomitous.

Perhaps there should be a multiple choice exam on the basics of aspect ratio before someone is allowed to purchase one of these sets.

Scott Wilkinson's picture
These ultra-widescreen TVs are very appealing, but we'll have to see how well they upscale the Blu-ray data from 1920x817 to 2560x1080. As for image stretching, it's a scourge alright. Can you imagine stretching a 4:3 image to 21:9? Actually, it should look hilarious!
Scott Wilkinson's picture
It's unrealistic to think that all movies should be made in a 16:9 aspect ratio. After all, they are meant to be totally immersive, which really requires a wider image than 16:9. LIke it or not, displayed visual images will continue to be created with different aspect ratios, so it's best to just accept that and find the best solution. For folks with lots of money, that solution is a projector with a 4-way masking screen, but for the less well-heeled, these ultra-widescreen flat panels might be pretty good.
javanp's picture

"As for image stretching, it's a scourge alright. Can you imagine stretching a 4:3 image to 21:9? Actually, it should look hilarious!" No kidding--the camera used to add 10 pounds, now it'll add a couple hundred.

javanp's picture

Scott, I'm actually in the middle of a discussion on AVS regarding which is more immersive (hrm, apparently that's not a word): 16:9 or 21:9. I was stating that 16:9 is not only more immersive, because it better fills up you field of vision, but that certain filmmakers (Cameron opting for 16:9 for Avatar) and film-technologies (IMAX) are opting to use narrower formats because of this. Someone (with some pretty obvious knowledge in the area of our vision) countered that while our field of vision is more square than rectangular, we are more sensitive to change on the sides of our visual plane than the top and bottom, hence making 21:9 more beneficial.

Personally, I like the idea of covering the whole field of vision--you can still frame the action within the frame to stay within the areas our eyes are most sensitive to, but I think that top-to-bottom, side-to-side coverage would better immerse us in the film than merely a super wide image.

Futhermore, I have this theory that the only reason formats went super-wide was because theaters were height restricted since stadium seating was not the norm (or maybe not used at all) back in the day. And because of that, we associate the super-wide formats with being more "cinematic" since all the major films wanted to be as on large a screen as possible. These days, the trend is reversing--the largest formats are square or square-ish.

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