Deciding on projector screen aspect ratio

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Deciding on projector screen aspect ratio is one of the hard aspects of building a new Home theatre room.

Conventional wisdom out there says that a new home theatre should have a 16:9 projector and a projector screen with aspect ratio 16:9 . While for some people that might absolutely be the right choice, it is good to be aware that there are other options worth considering and they could potentially provide a more dramatic viewing experience.

Almost all of the current televisions are in the 16:9 format and just because of this 16:9 seems to have become the de facto standard.

There are two alternatives worth considering depending on the type of material you prefer to watch.

Which of these formats is best for you? We’ll lay out the options and help you decide which way to go.

Aspect ratio

When we talk 16:9, we talk aspect ratio. 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 your screen. For 16:9 aspect ratio, this means 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.

One of the big advantages of a projector and a screen (apart from the awesome size) is that you have options. If you are going to use a television for your home theatre, you are stuck with the 16:9 format. These days televisions may come in all sizes but they are all 16:9 aspect ratio.

Not with a projector and a screen. Just browsing through the Rapallo projector screen section on the website will teach you that aside from the 16:9 ratio, you also can also opt for is 2.40:1 (or 2.35:1), commonly known as the Cinemascope format and the 4:3 format, the format of older televisions that were around from the 50’s.

Different image formats

Most films today are shot in the wider format 2.40:1 Cinemascope. This is especially true for big action/adventure films. Examples of films that were filmed in the 2.40:1 format are The Lord of the Rings, Star Trek, Casino Royale, The Bourne Identity, The Matrix. Just to name a few.

2.35:1 is the 35 mm anamorphic standard prior to 1970, used by CinemaScope (“Scope”) and early Panavision. The anamorphic standard has subtly changed so that modern anamorphic productions are actually 2.39 (2:40:1). But old habits die hard and 2.40:1 is still often referred to as 2.35.

The reason why some movie-lovers prefer a Cinemascope format screen because it matches the aspect ratio of a lot of movies being produced today.

On top of that, it’s hard to deny that the 2.35 format because it gives a more dramatic appearance compared to standard 16:9 widescreens. If a standard 16:9 picture is being displayed, and you switch to a wider 2.35 image, it looks even bigger and more impressive than the conventional 16:9 image.

So 2.40:1 Cinemascope must be best for movies, right?

Well, not so fast. While it is fair to say that most modern films are being done in the super widescreen 2.40:1 format, a few big ones are still in plain ol’ 16:9 (1.78). Probably the most popular titles in 1.78 are Avatar, The Godfather 1 and 2 and Tim Burton’s Alice in Wonderland.

Another format that is very close in aspect ratio to 1.78 is 1.85. This format was pretty popular in the late ’80’s and ‘90’s, so there is a decent sized library of 1.85 films on the market.

On top of a range of older movies, it is good to be aware that live music concerts as well as almost all HDTV content (such as news, sports, TV shows) are also often done in 1.78 or 1.85.

And then of course there is 4:3 for the real oldies.

I guess it is a simple (frustrating) fact of life that in the AV setups there are very few standards: Videos and movies screen ratios are no exception to the rule.

In other words, no matter what aspect ratio your screen is, you will end up with black bars at the top and bottom of some material, and black pillars at the sides of other material at some stage.

If you watch Cinemascope films on a 16:9 screen, you end up with somewhat larger black bars at the top and bottom of the image.

Meanwhile, when you put a 1.85 or a 1.78 movie on a 2.40:1 screen, the picture will be reduced in size with black columns on the sides.

The only time you won’t get black bars is if you are viewing video or film shot in the format of the screen.

So with that in mind, it sounds like it is as simple as figuring out in what aspect ratio the bulk of your viewing material is and you simply match your projector screen to that format. Well…not quite. There is more to the story than black bars and the formats films are available in.

Cinemascope screen downsides

While they are awesome and have serious WOW, there are also some undeniable downsides to a 2.35 screen: In most home theatre rooms, a 2.4 aspect ratio screen is going to be the smallest screen you can install. Watching 16:9 or 4:3 material on a Cinemascope screen will boil down to a much smaller image than you would end up with if you used a 16:9 screen.

Why? In the vast majority of home theatre situations, the room dimensions place a practical limit on the maximum width of the screen before placing any limitation on its height.

Let’s consider an example, to explain things: Let’s assume for arguments sake that the wall you are projecting onto is 4.25m wide and 2.7m high. You have some floorstanders that you want to place next to the screen, so you choose to leave 600mm on either side of the screen for speaker placement and aesthetic clearance from the side walls. Practically speaking, these room dimensions limit you to a maximum screen width of about 3m.

Knowing these measurements, it will be the width of the screen as opposed to the height of the screen that will determine what size will fit in your room. Even a 3m wide 4:3 screen wouldn’t cause any real issue height-wise, as it would measure 2.25m high. For 16:9 screen this would be a 1.7m high screen; for a 2.35 screen that is just 1.3m.

What this means is that the 2.35 format turns out to be the smallest screen you can install from a total square meterage perspective.

This is fine, if you only watch 2.35 material. But put a 16:9 image on a Cinemascope screen and your 16.9 image will be much smaller than on a 16:9 screen because the size of the image will be determined by the height. In other words: Your 16:9 image on the Cinemascope screen will smaller and have two black bars on each side.

Meanwhile, regardless of whether you use a 3m wide 2.35 or 16:9 screen, a film in Cinemascope format will be the same size on either screen. The only difference is that the 2.4 screen gives you a full frame effect, while the 16:9 screen will have black bars top and bottom.

For many people, this is the deciding factor in making the choice between a 2.35 screen and a 16:9 screen.

So, Deciding on projector screen aspect ratio while important, is quite a task.

Home theatre projectors and Cinemascope format

But say you decide you mainly watch movies in 2.35 format and you are just so wowed by the way a Cinemascope screen emerges you into the story that the pros out way the cons by a mile. There is still a final consideration to consider before making your final choice.

Deciding on a 16:9 vs. a 2.35 screen has an impact on the projector you ultimately select. Almost all home theatre projectors in the $1,000-$30,000 price range throw a native 16:9 image, so any home theatre projector is easily matched to a 16:9 screen.

Not so with a 2.35 screen. While there is definitely a lot to say for watching movies in their original (and definitely more impressive) Cinemascope format, you will need to match the projector with the screen.

Since there are no projectors available in 2.35:1 format, you have the option of three solutions:

The first option is to opt for a projector with a zoom lens that exceeds 1.3x in zoom range (preferably with powered zoom and lens shift and lens memory for ease of use. The bad news with that is -you guessed it-these are features reserved for the higher range models).

When viewing a 2.35 film, you zoom the lens to a wide angle setting such that the image perfectly fits the screen. When you switch to either 16:9 or 4:3 material, you use the powered lens to zoom forward until the image shrinks to the point that it fits the frame. If the projector is ceiling mounted and projecting at a downward angle, you may also need to use the vertical lens shift to realign the center of the image with the center of the screen. But with these two adjustments, you can easily achieve the objective of centering smaller 16:9 and 4:3 images in the middle of your 2.35 screen.

Sounds like a hassle? Well, it is a bit, especially without the above mentioned lens memory and powered zoom and lens shift. It may be the cheapest option, but it is probably not the most user friendly.

The second option is to include an external anamorphic lens in your projector set-up. An anamorphic lens is designed to distort an image by stretching it horizontally.

Anamorphic lenses were traditionally quite expensive, but thanks to companies like Prismasonic, they have now become more affordable. Prismasonic have developed an ingenious prisma based system that allows you to leave their device constantly in front of the projector lens. With traditional anamorphic lenses, you have to remove the anamorphic lens for viewing 16:9 movies, and put the lens in front of the projector for cinemascope viewing. The Prismasonic “lens” (it is a prism, in actual fact) can be controlled remotely to stretch the image horizontally, or leave the image as it is, without any stretch for viewing a 16:9 or 4:3 movie at a click of the button.

This leaves you to stretch the image vertically with the lens shift as described above.

So why opt for an anamorphic lens as opposed to work with a powered zoom and lens shift?

While definitely the more expensive option of the two, the anamorphic lens allows the use of 100% of the pixels on the projector’s display, resulting in a superior viewing experience with less visible pixilation.

If you have a 16:9 format projector, and you use the vertical stretch plus the anamorphic lens to produce your 2.35 picture, you use all the pixels to create the image. If you instead use the zoom lens adjustment (option 1) to blow up the picture, you end up using only about 75% of that.

Similar reasoning applies to the lumen output of the projector.

It is important to realize that with both options, subtitles will possibly not be visible. Often subtitles sit in the black bar below the image, and because of the vertical zooming of the image, the black bar ends up outside the screen and therefore becomes invisible.

A very elegant solution to this problem is offered by Oppo: For customers with a 2.35:1 home theatre set-up, Oppo bluray players allow for subtitle shift, so you can push the subtitles up into the visible image.

As a third option, you can consider the use of a video scaler/processor. On our website you may notice the ‘Lumagen Radiance’ range of products. The Lumagen Radiance range are regarded as the world’s best and most complete video processors; they will “zoom” the image digitally, without loosing any pixel information. On top of that they also feature a powerful colour management system and image enhancement technology amongst some other features. Their price is, although still hefty, typically lower than the traditional anamorphic lens.

Our advice – Deciding on projector screen aspect ratio

If your theatre involves a reasonable amount of HDTV content: Use a 16:9 format screen.

If your theatre is almost primarily for movies and you have a serious budget to play with: seriously consider a 2.40:1 format screen and add an anamorphic lens or Lumagen Radiance processor. The extra investment achieves such a dramatic experience that it’s really tempting to go there.

If you are a black and white movie lover, a 4:3 might be your best option.

For the sake of being complete, we would like to point out that Rapallo also stocks a range of 1:1 screens for more versatile use like data projection.

As so often, there is no such thing as a one size fits all. Everything depends on your viewing preferences, your willingness to make compromises when it comes to black bars, image size and pixilation and of course the money you are willing to put on the table. Welcome to deciding on projector screen aspect ratio.