TVs are great and all, but if you want really epic entertainment, you need a projector. One-hundred-plus inches of high-definition awesomeness.
Projectors, though, are a two-piece system. There's the projector that gets all the attention, and the lowly screen that actually lets you see an image.
There are many choices when it comes to screens. Here's what you need to know.
This is the important bit, obviously. Every projector creates a limited amount of light. As you increase the image size, you decrease the overall brightness. Most modern projectors can easily create a bright 100-inch image (pocket/pico projectors notwithstanding).
Here's a handy article I wrote on calculating brightness from the measurements in reviews.
Before you get caught up in lumen/footlambert/screen-inch minutia, consider your room. Presuming the average 8-foot ceiling, screen height is going to be the limiting factor. You don't want the bottom of the screen too close to the floor, as if you put your feet up (on an ottoman, etc.), they might interfere with your view. Also, where is the center channel speaker going to go? These are addressable issues, both necessary to consider before you get too set on an arbitrary screen-diagonal desire.
For most people, their room is far wider than it is tall (at least, I'd hope so), so if epic moving watching is your goal, consider a wider aspect ratio.
Aspect ratio refers to the proportions between the width of the screen compared with its height. All HDTV broadcasts are 16x9, so a 16-foot-wide screen would be 9 feet tall. This is also known as 1.78:1. Most big movies are wider, 2.35:1 or so (roughly 21x9). While nearly all projectors are also 16x9, there are multiple methods for showing 2.35:1 movies on a 16x9 projector on a 2.35:1 screen. As in, your screen doesn't have to be 16x9 just because the projector is.
The simplest way to fill a wider screen is to zoom out the projector. This allows the 2.35:1 image to fill the wider screen, but also means there will be some light spill above and below the screen. Fortunately, with most projectors, this is rarely an issue (after all, these are the black bars in the movie).
Another method is to use an anamorphic lens, like those from Panamorph. These require your projector (or an external processor) to stretch the image vertically (so everyone is tall and skinny), then a lens slides in front of the projector, stretching the image horizontally so everything looks normal. This wider image fills a 2.35:1 screen. Compared with zooming, with a lens you'll gain some light output (because you're using the whole DLP/LCOS/LCD chip for the image) and perhaps a slight amount of detail (thanks to scaling, and using the whole chip). The downside is you'll lose a little contrast ratio because of the additional optics. In my testing, the added brightness and apparent detail generally make up for the slight drop in contrast ratio.
I've mentioned before, I use a projector instead of a TV, and it projects on a 2.35:1 screen. For movies, it's awesome: a 10-foot-wide image that nearly fills your field of view. The downside to this method is that I use my "TV" most of the time for gaming. Games are almost all 16x9. So this means that on my screen, games occupy the center of the screen, leaving unused pillars of screen on the sides. I couldn't care less, but I know some people freak out at the idea of black bars. One way around this (while still getting a wider screen) is with masking. Most screen companies offer motorized masking that drops a material on the sides of the screen when you're not using it. It's also pretty cool-looking, like an old movie palace.
All screens have a "gain," or how much more they reflect light compared with a uniform reflecting surface (called a Lambertian surface). So a 2.0-gain screen reflects twice as much light than a 1.0-gain screen...sort of. Essentially what's happening is the screen "focuses" the light. So instead of the projector's image reflecting in all directions (a perfect Lambertian surface), more of it goes in one specific direction (ideally, toward your eyeballs).
This doesn't mean that a 2.0-gain screen will make a projector's image twice as bright as the same projector on a 1.0-gain screen, but it will be brighter. There are a lot of variables that mean the exact amount isn't quite as simple as a single number.
Because you're no longer uniformly reflecting the light, screen uniformity suffers. With high-gain screens, you can get "hot spotting" where the center of the image is noticeably brighter than the edges. Also, if you have a really wide seating area, the image isn't as bright for people in the side seats, as the light is "aimed" more for those in the good seats.
I don't recommend ultra-high-gain screens, at least not for most people. Most projectors these days are plenty bright, and I prefer a smooth, uniform image over a few extra footlamberts. It depends a lot on your projector and desired screen size, though.
In the early days of digital projection, gray screens were common. These "negative" gain screens improved the black level, a problem with early digital projectors. These days, contrast ratios and black levels have improved enough that I don't recommend "negative" gain screens.
That all said, I also can't outright recommend a specific screen gain, as I don't know your room, projector, or desired screen size. I'd recommend talking to a screen dealer, and find a gain/screen that matches what you're looking for.
You'd think that all screens are made of the same thing, but nope. The most basic screen is a smooth (usually vinyl) material that has a reflective surface coated on it.
There are also perforated and woven screens. These are if you want to mount speakers behind the screen. Having voices come the screen itself is cool, as is clearing your floor of speakers. However, you're going to lose some light with any perf/woven screen. In some screen sizes/viewing distances, you also might see the texture of woven screens (though you'd have to be really close/have a massive screen). Also, as "acoustically transparent" they claim to be, none is (it's physically impossible). So it's a trade-off, but in specific situations, a reasonable one.
Then there are rigid screens. I reviewed Screen Innovations Black Diamond Zero Edge, a rigid, ambient light-rejecting screen (image at top of article). When the projector's off, it looks like a plasma/LCD. A massive, massive plasma/LCD. The ambient-light-rejecting capability was cool, too.
There are also a number of other ambient-light-rejecting screens, but keep in mind, even the best can't compete with sunlight or a lot of room light. They'll be a lot better than a regular 1.0-gain screen, though.
So far I've generally talked about screens that you mount on a wall. Though more expensive, motorized screens can be mounted inside a ceiling (or floor!) and disappear when not in use.
For example, I have an Americana from Stewart. This model installs on a wall, and looks like big (OK, gigantic) wall sconce. Press a button, and a screen drops out of it.
One of the best uses for this (other than the cool factor) is the ability to have an inexpensive LCD for daytime viewing, and then drop down the screen for nighttime movies, TV, and gaming. A sort of "best of all worlds" approach. Given that you can get a great 50-inch TV for around $600 these days, this isn't as price prohibitive as it used to be. Especially when you consider the cost of 80- and 90-inch TVs.
OK, every time I write about screens, I get grilled on paint. As in, just painting a wall, either with regular paint or special projection-screen paint (like Screen Goo). When I've used walls as a screen, I've always seen the texture of the wall in the image. Maybe I'm just a crappy painter. (Maybe.) Many, though, proselytize just painting a wall. I'll say this, it's a pretty cheap option to try.
A few overall words of caution on paint. You need a really, really smooth surface. As in, sanding, painting, sanding again, painting again, and so on. Make sure you get a neutral color white, as any tint in the paint will tint the image. I'd recommend getting few varieties of paint in those little sample jars, and painting a swatch to see which looks best. If you've done this with some success, feel free to post about it below.
To be honest, I'm really not convinced this is the way to go, though. Screens aren't that expensive, and they'll always have less texture than a wall. Can't hurt to try if you're a DIYer.
Sheets and ceilings
All my words of caution with paint apply to sheets as well.
I've talked to a few people wanting a projector to put a "TV" on the ceiling while they're in bed. Some projectors are so cheap that this is certainly an economically reasonable option. However, it's not quite as awesome as it sounds. The problem is, you can't really change your viewing position. You can roll to the side a bit, but you don't have the variety of positions as you do when you're watching an image on the wall. Something to keep in mind, if you're envisioning long in-bed viewing sessions.
Though it involves a bit more of an installation, you can build your own rear-projection setup, where there's just the screen in the room, and the projector either in another room (behind the screen) or in a space behind the screen. Pretty much all projectors can do this, and there are specific screens made by many companies designed for rear-projection setups. Often these will come with mirror kits, so you have everything in one package.
Mating a projector with the right screen is crucial to get the best image possible from it. Figuring out what to spend is the real trick. Prices for screens range from a few hundred to many thousands. The inexpensive models may not have the gain, ambient light rejection, attractive aesthetics, motorization, and other features of the more expensive models, but they should offer a smoother picture than paint on a wall.
For example, I haven't tested them, but Elite has multiple inexpensive screens on Amazon. This 120-inch manually retractable screen, to pick one, is $150 and has four out of five stars from 330 reviews. There are other inexpensive screens on Amazon from Da-Lite, Monoprice, and others, but most don't have user reviews.
Personally, I use a 10-foot-wide, 2.35:1, 1.0-gain, Stewart Filmscreen StudioTek 100, as it was the largest I could fit in my room, and the gain makes measuring projectors easier. I wouldn't recommend that gain for most people (they make many other gains).
When I was at Home Theater I used a 1.0-gain Da-Lite Da-Mat that held up to years of abuse.
Got a question for Geoff? First, check out all the other articles he's written on topics like HDMI cables, LED LCD vs. plasma, Active vs Passive 3D, and more. Still have a question? Send him an e-mail! He won't tell you which TV to buy, but he might use your letter in a future article. You can also send him a message on Twitter: @TechWriterGeoff.