Building Your Own Home Theater
Evan Powell
ProjectorCentral.com


Choosing the Right Aspect Ratio

The first and most important decision you can make about your new home theater is this:

What screen aspect ratio do you want: 16:9 or 2.4?

What is aspect ratio, you ask? Aspect ratio is the ratio of the width of the screen to the height of the screen. Essentially, it describes the shape of the rectangle. Today the most popular aspect ratio for consumer video display is 16:9, which is the standard HDTV format. The numbers mean that the picture is 16 units wide for every 9 units in height.

Sometimes you will see the 16:9 aspect ratio referred to as 1.78:1, or simply 1.78. Why? Because 16 divided by 9 = 1.78. But it means the same thing. A 1.78 screen is 1.78 units in width for every unit of height.

If you are going to use a flatscreen HDTV for your home theater, you are stuck with the 16:9 format for better or for worse. Though they come in a wide variety of sizes, they are all 16:9 aspect ratio. But if you are planning to use a projector and screen, you have another option, which is 2.4:1, commonly known as the Cinemascope format. This is a wider format than standard 16:9. Many people prefer it because it matches the aspect ratio of a lot of movies being produced today.

Think about the black bars

Here is a simple fact of life: Videos and movies are made in a variety of different aspect ratios. There is no standard. So no matter what aspect ratio your screen is, you will always end up with black bars at the top and bottom of some material, and black pillars at the sides of other material. The only time you don't get black bars is if you are viewing video or film shot in the format of the screen you are using--either a film done in 1.78 displayed on a 16:9 screen, or a movie shot in 2.4 on a 2.4 Cinemascope screen. In both of those cases, the screen frame will match the picture precisely, and no black bars will exist.

(By the way, we're assuming you want to see the material you watch in its correct original aspect ratio, as the director created it. If you don't, there are several ways to stretch, manipulate, or crop video images to get them to fill a 16:9 screen and eliminate the black bars.)

So in choosing between a screen aspect ratio of 1.78 vs. 2.4, you are really deciding how the various film and video formats will appear on your screen. For example, if you select a 16:9 screen, all of your 2.4 format movies will have black bars top and bottom. If you select a 2.4 screen, all of your 16:9 material will be "pillar-boxed" in the center of the screen with black columns on each side.

So 16:9 must be best for HDTV broadcast, and 2.4 Cinemascope must be best for movies, right?

Well, not so fast. Many people assume that all modern films are being done in the super widescreen 2.4 format. They aren't. A few, including some new and popular titles, are done in plain ol' 16:9 (1.78). As examples, here are some movies that are either done in 1.78, or have been modified to 1.78 for Blu-ray...

Avatar
Tim Burton's Alice in Wonderland
The Hurt Locker
The Godfather
The Godfather II
The Shining
Blade Runner (1.66)
Finding Nemo
Toy Story
Up
Beauty and the Beast
The Little Mermaid
The Shining
A Clockwork Orange
Charlie and the Choc. Factory
The Pelican Brief
Planet Earth
(documentary)
Michael Jackson's This is It

But beyond some films and all of the HDTV broadcast programming that are done in 1.78, many live music concerts on Blu-ray are in 1.78. Once you get into 1080p home theater, many people like to experience music concerts in HD on the big screen. Some of the concerts on Blu-ray that are done in 1.78 include...

Roy Orbison, Black & White Night
B.B. King Live at Montreaux
Eric Clapton/Steve Winwood
Diana Krall Live in Rio
Chicago/Earth, Wind & Fire
Elton 60

And in addition to 1.78, there is 1.85

Another format that is very close in aspect ratio to 1.78 is 1.85. This format has been popular for a long time, so there is a huge library of 1.85 films on the market. Examples of movies done in 1.85 include....

Saving Private Ryan
Scent of a Woman
Good Will Hunting
Rain Man
The Big Lebowski
Fargo
The Silence of the Lambs
Jurassic Park
Edward Scissorhands
Back to the Future
Shrek and Shrek 2
Dead Poets Society
Risky Business
My Cousin Vinny
The Verdict
Sleepless in Seattle
Pretty Woman
Sideways
Rising Sun
Ice Age
Sherlock Holmes
The Bucket List
As Good As It Gets
Lost in Translation
P.S. I Love You
The Wedding Singer
Monsters Inc.
District 9
Sex and the City
Goodfellas
The Exorcist
The Blind Side
The Shawshank Redemption
Rocky
Raging Bull
The French Connection
North by Northwest
Psycho
Vertigo
Chicago
A Beautiful Mind
Serpico
Good Morning Vietnam
The Dirty Dozen

Not only are there scores of movies on Blu-ray in 1.85, but live music concerts appear in this format as well. A few examples include...

Eagles Farewell 1 Tour
Diana Krall Live in Paris
Led Zepellin
Willie Nelson/Wynton Marsalis play Ray Charles

So, the bottom line is that when planning your home theater, it is a good idea to anticipate you will be viewing a reasonable amount of video and film content in either 1.78 or 1.85, as well as the wider 2.4 format.

How do you fit 1.85 movies on a 1.78 screen?

There are two ways to watch 1.85 material on a 1.78 screen. The first option is to set the projector's lens so it just fills the 1.78 screen with a 1.78 image. When it is set this way, all 1.85 movies will be shown with very tiny black bars at the top and bottom. On a 120" diagonal screen, the black bars would be about one inch each at the top and bottom. Many people think this is no problem, so they set it up this way so that 1.78 material fits the frame perfectly.

The alternative is to set the projector's lens so that a 1.85 movie fills the screen vertically. When you do this, you cause the picture to overshoot the screen surface. Those tiny black bars fall onto the screen's frame top and bottom, which is good, but you lose a bit of the picture on the sides. Meanwhile, 1.78 material overshoots the screen surface on all four sides. But if you can live with the small amount of edge cropping, you end up with all 1.78 and 1.85 material filling the screen with no black bars. You lose about 2% of the image on the sides for 1.85 material, and 2% on all four sides for 1.78. In situations were you must see the 1.78 image 100% full frame, you can adjust the projector's zoom lens to reduce the image to get it entirely onto the screen. For many people this is an acceptable compromise.

As a side note, if you like the idea of living with minor edge cropping to get rid of the tiny 1.85 black bars, a better alternative would be to have your screen cut to 1.85 instead of 1.78. When you do this, all 1.85 films will fit perfectly without those tiny black bars. Meanwhile, material in 1.78 will slightly overshoot the top and bottom edges of the screen, but will remain fully visible on the sides. On a 120" diagonal screen, about one inch of the top and bottom of the 1.78 image would fall onto the frame, which is less than 2% of the image on both edges--not much of a sacrifice. On occasions where you absolutely must see the entire 1.78 image, the projector's zoom can be adjusted slightly to reduce the image size, resulting in small black columns on each side. But this set up eliminates both black bars and image cropping on 1.85, and limits cropping on 1.78 to just the top and bottom, rather than all four edges.

Which of these options is the better choice depends on what you watch most frequently. If you watch a lot of HDTV broadcast content, you will probably want to see it full frame. Assuming the tiny black bars on 1.85 are not a concern, the 1.78 format screen will be the best choice. If you don't watch much TV, and your primary objective is seeing 1.85 movies full frame without edge compromises, then the 1.85 format screen is the better choice, at least between these two very similar formats.

Okay then, what about the 2.4 films?

Obviously, most films today are done in the wider format 2.4 Cinemascope. Part Two of this article will focus on the display of 2.4 movies, and the selection of the 2.4 format screen as an alternative to conventional 16:9.

Continue reading Part Two, The 2.4 Cinemascope Option


Reader Comments(17 comments)

Posted Jan 5, 2014 9:17:29 PM

By Ben

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"What screen aspect ratio do you want: 16:9 or 2.4?" Thank you for a very well written article on the subject matter. There is a lot of useful information here. I built my dedicated home theater 13 years ago. It is now undergoing the upgrade number 3. Affordable HD projectors made all the difference when it came to enjoyable watching of the movies. One thing that I have not been able to avoid are those "black bars" on the 16:9 screen. Everybody calls them black bars when in fact I can only see dark grey at the best of times. Since I watch only movies in my theater, I would love to have a projector with the native 21:9 aspect ratio. I can't get one! Changing the screen is an easy problem to solve. But projector... Your article gives pros and cons of various aspect ratios of the screen. It appears that the amount of the real estate of the screen surface was an important issue. For some people it may be so. The widest possible 16:9 screen in a room may produce the largest screen area and a wow factor. However, I fail to see how a huge 16:9 screen is going to improve the quality of the image with the current crop of projectors. I am talking about the loss of vertical resolution here of course. By the way I dislike the usage of an anamorphic lens. My argument is: The vast percentage of the movies are released on DVD/BD in original theatrical aspect ratios, so why no projectors to cater for this format. 16:9 screens do nothing for the quality of the image.(good for TV sports etc.) I would like to see 21:9 projectors available, or somehow force movie studios to release all Blu-Ray discs in 16:9 aspect ratio. I'll keep on dreaming. Regards, Ben

Posted Jan 18, 2013 7:05:47 PM

By John Higbee

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Good article, Evan. Seems to me a straightforward approach is simply to match screen aspect ration to the native resolution of the projector. That way, you'll be seeing the best the projector can do with any given content. An HD projector will fully fill a 16:9 (1.78:1) HD screen with HD content (sat or cable HDTV, Bluray). Sure, standard-def (DVD) content will display in a more narrow image, with black pillars on the sides. But that's to be expected, as are the minor top and bottom bars that result from showing ultra-wide-screen movie content with an HD projector. As you point out, trying to make black bars go away forever involves either significant picture compromises, or expensive projector lenses/automation. Or post-display tweaking (e.g. screens with variable masking).

Posted Sep 25, 2012 2:34:07 PM

By JDoug

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I'm sorry your revision omits the "old" 4:3 format for TV screens, which we have at home and everything looks fine on it (with Verizon FiOS cable). On vacation recently we were in a flat with 16:9 TV, and all, ALL!, the images were disturbingly fattened sideways. All, ALL!, the people looked very stout or fat - tolerable for football and baseball players, maybe, but not for ordinary people on screen. The TV did not allow the format to be changed, either, so we were stuck. Long live 4:3 screens!

Posted Jul 11, 2012 6:54:46 PM

By Ronin

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B lade Runner was filmed in 2.4, not 2.35.

Posted May 24, 2012 3:08:39 AM

By Jan A

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It is often argued that 21:9 is to remove the black bars on whide-format movies - which is rather subjective of nature, and very visual.

There is in fact another view, which is more quantitative and "scientific". On a 16:9 screen to watch the movie in the same size, whide-format movies are down-scalled, or rather the source is down-scalled and black bars are inserted. Meaning the optimal sitting distance changes when you change movie-format. You have to move closer when watching a down-scaled movie ( when watching Cinemascope material ).

If you consider a 50" 21:9, it is often argued why not get a 60" 16:9 instead - well, apart form the problem of space, there is the old problem of optimal viewing distance - on the 60" 16:9 content will be blown up to a huge format, giving less picture quality and you have to move further back to get an optimal viewing distance each time you change format.

On a 21:9 TV set, there is no up- or down-scalling of either 21:9 or 19:9 contents, the viewing distance is the same on both formats. Then you of cause instead have the black bars at the sides - but on the positive side you can streach the 16:9 content if you like - you have the option.

So its about angle of view ;-)

Posted May 22, 2012 12:24:01 PM

By Kenny

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How about 16:10 which is on my tablet. Which projector do you recommend if I want to watch movie and play games

Posted Jan 18, 2012 10:37:09 AM

By Tim

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I am really confused. 16:9 and 4:3 would seem to be the same ratio as would 158:118.5 Maybe I need a picture to understand.

Posted Sep 2, 2011 6:10:11 AM

By Washington

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Not very clear. I didn't understand what is 1.78:1, 2:35.1 etc. A draw would be nice.

Posted Aug 25, 2011 9:39:48 AM

By Khamani

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Thanks! Very helpful & insightful! :)

Posted Aug 17, 2011 8:28:21 AM

By Peter Riedel

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Blade Runner was actually filmed in 2.35:1 35mm and released also in 2.2:1 70mm - not 1.85:1 or 1.78:1 format.

Posted May 16, 2011 11:45:38 AM

By GPSOFT

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ALL THING ARE RIGHT BUT ORIGINAL WATCH "CINEMA" MOVIES WATCH IN 2:40.1 SCREEN IT'S ORIGINAL THEATER SCREEN, AND 16:9 IS ONLY TV "aspect ratio" NOT A HOME THEATER SCREEN...............

Posted Mar 24, 2011 6:52:01 PM

By Paul Freeman

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Dear Evan, Soon I will purchase a JVC DLA HD-250. My question is if I purchase 2.35 screen, I have already purchased a 16x9 portable, and watch 2.35 without having to purchase an anamorphic screen? My setup requires portable as much as I would like fixed.

Part of me says spending as much for a lens as the camera might not be good at this point, maybe later... Great articles regarding screen size and preference, thanks.

Posted Nov 12, 2010 5:33:08 AM

By Alex Teusch

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For your information, Philips has a wonderful 21:9 LCD TV! (link deleted)

This will be my next buy when my current HDTV is up for replacement.

Posted Nov 5, 2010 5:45:13 PM

By Sifu

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If you want to have the biggest screen possible inside your room. A lot of time, a major limitation (in additional to money) you encounter is your ceiling height or image height allowed.

At the same ceiling/image height, you can fit a much bigger 2.35 or 2.4 aspect ratio screen than a 16:9 screen inside your room.

Posted Oct 27, 2010 12:11:41 AM

By Evan Powell, Editor

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Thanks Stephen and William, not sure how those titles got miscategorized, but I corrected it. Thanks for the feedback.

Posted Oct 26, 2010 4:28:09 PM

By Stephen Totleben

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This is true. Also Forrest Gump,Invictus and all the Harry Potter movies were 2:35.

Posted Oct 26, 2010 1:47:29 PM

By William Carman

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This was a very interesting and well written piece.

However, I need to point out that the movie "SE7EN" is not 1.78:1 as stated on your first list, but is 2.4:1. (I have this in my Blu-ray collection as it is one of my favorite films.)

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