What is a projection screen and what is it used for?
A projection screen is a large reflective surface, usually white, that’s typically hung on a wall in a room at some distance in front of any type of digital or film projector for the purposes of entertainment, training, education, or sales presentation. Compared to a bare wall, a projection screen affords higher reflectivity, resulting in a brighter picture. A screen also bestows a more uniform image surface and truer color rendition. Still, there are special paints that can be applied to a wall in lieu of a screen.
Why choose a projection system?
If you’re buying a screen, you’re already sold on the dramatic advantages of a projection system: picture size that dwarfs almost any TV, scalability without necessarily buying new equipment, and the elimination of overt letter-boxing or columns that TV viewers often find distracting when the program’s aspect ratio is different from the TV geometry. Also, when you combine the cost of screen and projector, you can’t beat the per-inch value of a projected picture compared to the biggest TV you can find.
What venues can be served by projection screens?
Conference rooms, board rooms, classrooms, auditoriums, and movie theaters are the most likely spaces to sport a permanent screen. But the leading locale is a room in a private home used as a home theater. Given the variety of settings and applications, projection screens are available in a wide range of sizes and prices.
|Large Venue||Multimedia||Home Theater|
What’s the difference between a data/multimedia projector screen and a home-theater projection screen?
Not much. Since both types of projectors can be hooked up to a computer, Blu-ray Disc player, DVD player, game console or cable box, the screen doesn’t care what type of content is thrown at it. More important distinctions are made regarding screen size, aspect ratio, amount of reflectivity and how the screen fabric is stored when not in use.
Do you need a dedicated room where the projection screen will be deployed?
No, but if you’re fortunate enough to have a dedicated home theater room, a screen mounted to the wall or ceiling will serve your needs. Most people use a TV to watch movies, sports, TV shows, concerts, and home videos or play video games and view slide shows. But when the occasion calls for it, why not widen the canvas, perhaps in the same room as the TV? Call it your multi-purpose room. When the projector isn’t being used, you should be able to hide the screen.
What is aspect ratio?
Aspect ratio in screens is just like aspect ratio in TVs and computer screens—16:9 and 4:3 are two common aspect ratios you will likely have heard of. It is simply the ratio of the width of the screen to its height. In the instance of a 4:3-ratio screen that is four feet wide, the height will be three feet. Typically, you will want to select a screen that matches the native aspect ratio of your projector. HD projectors, whether 720p or Full HD (1080i/p), will be 16:9, multimedia projectors that are XGA format will be 4:3 (sometimes called "Video" or "NTSC" format), while "HD-friendly" WXGA and WUXGA multimedia projectors will be 16:10. 4K projectors can either be 16:9 (3840 x 2160) or (4096 x 2160) 17:9. The way to know is to look at your projector's highest native resolution. From this you can use a calculator app or make a quick online search to find out what the corresponding aspect ratio is. Keep in mind that the highest native resolution may not be the highest input resolution. An XGA-resolution projector may be able to accept a 1080p image; however, the projector will either have to letterbox the image or stretch it vertically to fit its native 4:3 frame.
Comparison of four of the most commonly encountered aspect ratios
To recreate the movie-theater experience, one also has the option for variable aspect ratio screens. They are typically fixed-frame wall-mounting screens that include a motorized masking system that adjusts to fit the content you are viewing. They can give you truly cinematic aspect ratios, such as 2.35:1, a frame nearly 2.5 times wider than it is high. Depending on your projector, curtain operation may be automatic, based on the signal the projector receives, or there may be a remote you use to select the size.
Is the manufacturer talking width or diagonal, regarding screen size?
Traditionally, projection screens have favored screen width as the primary measurement, while TV/monitor makers have favored diagonal size. Width is import for projection both because it is defined by throw ratio and because it gives you an idea of what will work in a given space. However, as screen makers have started to see themselves as competing more and more with large-screen TVs, they have shifted their measurement standard to diagonal over width. Ultimately, width is still more important; however, the diagonal measurement does give you a comparison, size-wise, to a TV.
Both diagonal size and screen width are important when selecting a projection screen.
How big a screen do you want?
In the home theater environment, 100" or larger is generally considered the threshold above which a screen becomes worthwhile over a flat panel. A great deal will depend on the throw ratio of your projector. Throw ratio is distance relative to the width of the screen. For example, with a 1.5:1 throw ratio, at 15 feet, the projector will throw a 10-foot wide image. Projectors with zoom lenses have a throw-ratio range, giving you some flexibility, and many so-called installation projectors have interchangeable lenses. If you select the incorrect screen size you will either end up with an image spilling off the screen, or have an image that doesn't fill the screen. Obviously, you are selecting a screen in advance of knowing what projector will be used; erring on the side of too big is your safest bet.
You will also need to consider screen placement. Is the screen high enough up that anyone in the audience can see the bottom? Is it far enough away from side walls to enable favorable viewing angles? Is it large enough that the least favored viewer can see the image clearly? Generally, it is recommended to elevate the bottom of the screen at least four feet from the floor (possibly a little less in a small setting, such as a living room). Additionally, the screen height should be about 1/5 the distance of the farthest (least-favored) viewer. This translates to a four-foot-high screen for an audience member sitting 20 feet away. Of course, this is just a general rule of thumb. Content such as a presentation involving lots of detail or smaller text may require a large size. Also keep in mind that screens, like any other type display (especially LCDs) have an optical viewing angle. This will depend on the surface. High gain (i.e., "brighter") screens tend to have lower viewing angles (viewing cones) than more neutral screens like matte white.
Be sure to leave enough clearance between the walls and the floor when installing your screen; at least four feet from the floor and 6 inches from the adjacent wall.
What is a motorized screen?
Usually, motorized refers to what we think of as a conference-room screen; a wall- or ceiling-mounted screen that descends on command (or even automatically as the projector is turned on). Some feature external housings that are often offered with different finishes or veneers to help match the aesthetics of the room in which they are placed. Alternatively, there are ceiling-recessed screens, which are installed completely above a drop ceiling. A trap door on the bottom of the enclosure hides the screen when it’s not in use. The screen can then be controlled via a wall switch, remote control, through a room automation system, or by connecting to a special low-voltage trigger port on the projector.
In some cases, portable floor-standing screens are also motorized. These are ideal for staging applications. They will rise up from the floor rather than drop down.
What is a manual screen?
A manual screen is a wall- or ceiling-mounted screen a lot like its motorized cousin; but with a pull-cord rather than a motor. Many feature controlled screen return to so that the spring mechanism doesn't cause a violent "snap" as the screen ascends back into its housing. Apart from being more cost effective, manual screens weigh less than motorized equivalents.
What’s a tripod screen?
Easily stashed away in a broom closet when collapsed, these portable projection screens contain three legs that snap in place to support a screen that you manually extend like an inverted shade from its rolled-up base. Aspect ratios are available in square, 4:3, or 16:9 (rarely wider) and diagonals range from about 60 to more than 100 inches. Setup is fast compared to other portable, like folding screens. Since most open "up" rather than expanding out to either side, the case will be slightly longer than the width of the screen, so bear this in mind when considering transportation. If you need greater portability, consider a folding screen.
What is a folding screen?
A folding screen is a type of portable screen that detaches from a frame or truss and folds up, packing away neatly in a box. Folding screens are the most portable (besides ultra-compact tabletop screens), and have the advantage of being able to have screen material swapped out easily—say, to change from front to rear projection. The drawback is much higher cost compared to tripod screens of the same size. Many have optional drapery kits to conceal the truss or frame and work with masking to support different aspect ratios.
What is a floor screen?
A floor screen is a portable screen like a tripod screen, but without the tripod. A scissor mechanism or other kind of support to hold the screen up and a length of black is provided at the bottom to raise the viewable part sufficiently off the floor. They are basically large versions of tabletop screens. Most often manual, a few motorized models are available, as well.
What is a tabletop screen?
This is a mini floor screen that can be thought of as a portable substitute for a monitor or TV. The smallest are meant for use with pico projectors and can be packed up as easily as a notebook computer. A popular choice is a screen with a 25-inch diagonal when unfolded. But larger screens that fold up like an accordion during transport are available, too.
What is a fixed-frame screen?
Fixed-frame screens mount directly on a dedicated wall space, much like a large flat panel. They are the screen type most movie theaters use. The advantage of fixed frame is lower weight than motorized retractable screens, meaning they can be mounted to virtually any wall. Some also break down for easier transport and reduced shipping costs. If there is an opening behind the screen, they can be used for rear projection. With a perforated screen surface, the center and left and right channel speakers can be placed directly behind the screen. The perforations enable acoustic transparency without impacting image quality noticeably. Because of the ease of installation, fixed-frame screens are extremely popular for home theater installations.
Is tension a good thing for a screen?
Many wall- and/or ceiling-mountable screens will be available with or without tensioning. Tensioned models attempt to keep the fabric flat and immobile, while non-tensioned models have the screen fabric hanging freely from their support structure and are likely to move if there’s a breeze from air conditioning or people milling about, causing momentary imperfections in the projected image. Tensioned screens are also tauter, providing a flatter viewing surface. The flatter the surface is, the better focused the image will be. All in all, tensioning is a good thing, but may be something you can live without, depending on the application.
Tensioning pulls the screen taught to make the viewing surface as smooth as possible.
What screen surface should I choose?
Gray, matte white, high contrast, glass bead... the options go on and on. These days, if in doubt, plain matte white is probably the safest bet, as it is the most versatile. Other screen surfaces may yield better results in particular situations, but for any benefits there will be tradeoffs. For example, high-contrast screens can help projectors with weaker contrast ratios produce better-looking shadows (the darker parts of the image) but, as a side effect, will have lower gain, making the image less bright. High-gain screens can help a lower-brightness projector overcome ambient light at the expense of reduced viewing angles and increased "hot spots." Glass bead is a surface you will want to avoid. Generally, screens that offer glass bead are intended for legacy technologies like CRT projectors or slide projectors. You may get inferior results (such as lowered resolution) if using them for modern digital projectors.
What is screen gain?
The material that a screen is made of determines the amount of its reflectivity. High gain (more than 2.0) screens are useful when the projector isn’t very bright (as in a pico projector) or in rooms where there’s more ambient light than you’re able to shut out. Though high-gain screens brighten the image, they may do so by narrowing the optimal viewing angle and often at the expense of color purity, uniformity in brightness, and resolution. A medium-gain (1.1 to 2.0) screen can be moderately helpful in compensating for a less-than-robust projector. By choosing this type of screen, negative effects such as hot-spotting and a drop-off in off-axis viewing brightness are ameliorated. Low-gain (1.0) screens reflect light uniformly without the tendency of a high-gain screen to gather its reflective output toward the center of the viewing area. What’s good about a low-gain screen is that it will afford about the same brightness, no matter where audience members are sitting.
Are HD and 4K a factor?
At one time it was claimed "a screen is a screen, it doesn't matter what you throw at it." Lately, screen makers have started releasing HD- and 4K-optimized surfaces. Because no screen is perfectly reflective, it stands to reason the quality of the surface will impact picture resolution. Unfortunately, for the moment there is no clear standard for measuring what impact screen material has on resolution. This makes it difficult to distinguish hype from a true improvement in performance. If the screen is being used for a critical viewing application, independent reviews should be your guide. For more "practical" usages—conference rooms, for instance—subtle variations in fidelity are unlikely to be noticed.
Do you want a perforated screen?
You may hear "perf" or "perforated" come up when exploring screen surface options. Perforated is not technically a surface material—often the same material will come in a perforated and non-perforated version. The perforations are tiny holes that enable acoustical transparency, allowing you to place center and front channel speakers behind the screen. This surface type is common in home theaters with fixed-frame screens and in movie theaters.
Is there a rear projection screen option?
If you can find space behind the screen, rear projection is always an option. Advantages include no risk on an audience member casting a shadow over the image, and no ugly projector and mount hanging from the ceiling in the middle of the room. In the case of fixed-frame screens, the projector can be placed in a recess behind the screen that is walled off from the auditorium or viewing space. This creates a built-in look, as though the screen were a giant flat screen TV hanging on the wall. Drawbacks include the requirement for dedicated space for the projector and the fact you will need a short-throw lens—possibly coupled with a burlesque apparatus of mirrors—to make it work.
There are also "dual vision," or front and rear projection screens. These surfaces are most common on folding and truss screens, as they allow the same screen system to be adapted to a variety of venues. Similar to dual vision, in public settings you will sometimes see semi-opaque, suspended screens that can be viewed from either side. The obvious drawback to these screens is that the image will be reversed on one side.
What about a paint-on screen?
If you have a wall in front of your projector that is characterized by a uniformly smooth surface, you can buy special paint in one of several shades. Gray will provide better contrast than white, but white reflects the brightest picture. Don’t forget the paint tray and roller. See “Who Knew B&H Sells Screen Goo?”
Are there outdoor screens?
Tripod and fixed-frame screens are frequently used outdoors. They are not weather resistant and, since they work almost as well as sails as they do at bouncing light, precautions must be taken in order to anchor them or weight them down. For backyard use, inflatable screens are a popular alternative. They are more cost effective than folding screens and take up less space when not in use. They also tolerate a splash or some rain (though your projector may not!). To spare your lungs and equilibrium, an air-mattress-style pump is usually included.
What control options do screens have?
Electric screens usually have a basic wall switch included. In addition, they may work with RF and/or IR remotes, RS-232, Ethernet, and low-voltage control (LVC). IR and RF are simple handheld remotes, like a TV remote. IR requires line-of-sight with a receiver "eye," while RF just needs to be within radio range. RS-232 (or other serial interface) is a serial port that enables control by either a more advanced wall switch or a third-party control system. If you have a home automation system, there's a good chance you can link it to a screen with RS-232. Ethernet does much the same, but is more general purpose—you can use software on a computer or, now that we live in the era of the "Internet of Things," possibly control your screen from the other side of the world (why you'd want to, who knows?). Low-voltage control (aka low-voltage trigger, 5 to 12V trigger, video projector interface, and other names) is a simple binary interface telling the screen to raise or lower. A wall switch may use LVC and many projectors have LVC trigger ports so that you can have the screen lower when the projector is turned on and rise when it is turned off.
What types of screen accessories are available?
The accoutrements of a well-dressed screen can help protect the projection surface, make the screen more aesthetically appealing in its integration with the room, absorb sound and light or, in the case of a portable screen, make it easier to transport. Accessories mostly fall into two categories: hardware and woven-ware.
Mounting hardware (brackets and screws) will be included for almost any screen meant for installation on a wall or ceiling. The motor and a remote control will almost always be included, too, for a screen capable of lowering itself. More complex setups may require additional mounting hardware. In the case of a screen used in training, or educational settings, you may want to opt for a laser pointer.
The softer side of screen accessories encompasses drapery, skirts, and wings. Drapes or curtains can be used to hide a screen fixed to a wall when the projector is idle. Winged drapes flank the screen to focus the audience’s attention during a presentation. A skirt is mounted below the screen. A zippered carrying case can be used to transport a portable screen.
- A retractable screen (motorized, manual, or portable) makes the most sense for a multi-purpose room, since the screen can be hidden when it isn't being used.
- If you can't install the screen, a tripod is the way to go. But if you need ultra portability, consider a folding screen.
- Movie lovers will want a screen with an aspect ratio of at least 16:9, maybe wider.
- Projection screens are as often identified by width as by diagonal, so make sure you're on the same page as the manufacturer.
- A matte-white screen is the most widely used screen type, but a slightly gray screen may help achieve greater contrast in certain circumstances.
- A perforated screen enables one or more speakers to be placed behind the screen.
- By taking the projector out of the auditorium, rear projection helps make the experience about the content rather than the equipment.
- A high-gain screen helps compete with ambient light or compensate for mediocre projector brightness.
- Consider control options for integrating your screen with an automation system, or linking it to your projector.