Selecting a projection screen for educational facilities is a specific process just like it would be for any other business application. However, there is no reason for it to be a overly complicated or expensive process. The four main criteria are Projector compatibility, image size, lighting and function. In previous conversations, I have often referred to the latter as "environment" for the benefit of simplification. However, I believe that "lighting & function" really covers the broad spectrum of where the screen will be mounted and how it will be used.
First of all, projector images come in different shapes or aspect ratios. The aspect ratio is the correlating height to width units of measurement for an image footprint. For example, a 16:9 aspect ratio means that for every 16 units of measured width a screen has, there will be a correlating measurement of 9 identical units vertically. Here is the basic rundown on the most common aspect ratios in schools, churches and other training facilities today:
• The 1:1 or "squared" aspect ratio is just that, a square. It is most commonly used with overhead projectors and in celluloid slide shows. (Kinda' old-fashioned now.)
• The 4:3 (or NTSC) is the standard shape for "old-school" televisions and computer monitors. It is also the most common format for commercial applications and computerized slideshows.
• HDTV, the 16:9 ratio the standard television aspect ratio. It is the most commonly used format in home theater installations.
• The new 16:10 (or WXGA) aspect ratio accommodates the latest computer formats and is more compatible with standard HDTV (16:9). Because of its versatility, there is a growing demand for 16:9 and 16:10 aspect ratios it is growing in popularity with commercial applications.
In order to maximize the professionalism of your presentation, the image should be properly matted to the screen. For this reason the projector and screen should have a shared aspect ratio. Second, the material needs to match the projector's performance. Over 90% of the time, a matte-white material is appropriate. It has a wide viewing angle that accommodates the wide spectrum of viewing directions of individuals throughout the room. Most commercial projectors pack the punch to work with a matte white material. However, specialized "ambient light rejecting" and rear projection materials are sometimes necessary due to excessive ambient light issues. (We'll get to this in a moment.)
This is essential to providing the highest degree of image visibility without overpowering the viewers. Too small an image is unimpressive, too big and the viewers will either get a stiff neck or miss out on the peripheral view. This is the same reason why the very front row seats of a movie theater are always the last to fill. As a rule of thumb, get your projector first and then project it on the wall. Increase the size until it is large but not too big for everyone in the room. Check this from your various seating positions; take note of it; and select your screen size accordingly. It will generally be 84-120" (diag.) for most meeting or class rooms and 150" to 400" for large conference halls and sanctuaries.
Ambient light comes from sources other than the projector and is notorious for washing out images leaving a dull, "milky" picture instead of a sharp image with clear colors and detailed contrast. Ambient light can be negated in three ways. Either by using window shades and lighting control keep it from washing out the projected image; getting a more powerful projector, or by increasing the brightness of the projected image with a specialized material. Since we are talking screens we'll focus on Ambient light-rejecting materials. They use a highly-reflective surface to concentrate the projected image back to the viewers in a more narrow "viewing cone" while its shaded contrast filter layers keep ambient light from washing out the picture. However, this material is more suitable for traditional sanctuary or theater seating since the image loses its brightness for viewers seated too far to the side.
There are many environments and just as many screen designs to suit them. Here are a few:
• A fixed frame screen is desired because it is comparatively lightweight so that it is easily hung up and it requires very little maintenance. Fixedframe screens have a very professional "home theater" appearance so they would not be my first choice for a school but there are exceptions.
• Roll-up projection screens are best for multi-purpose rooms and come low-cost solution for smaller congregations. If the screen is going to be mounted in a hard-to-reach location, it will be better to get an electric version that has both infrared (IR) and radio frequency (RF) control options.
• Free-standing projection screens are ideal for environments where the architecture makes floor, ceiling or even suspended installations impossible. These are available in either manual or electric configurations. They operate in the same manner as retractable "wall-ceiling" screens do but go from the ground up. They usually come in sizes up to 200" and require no costly installation while taking up little room when stored.
• (Okay, I saved the best for last) The whiteboard/projection screens are a relatively new concept but are essential for classrooms. Whiteboard-projection screens are professional-grade projection materials that have been specially treated to function as dry-erase "whiteboards." I cannot say enough about how absolutely great these products are in educational environments. They combine the whiteboard and projection screen into one item thus negating any possibility of a mechanical failure which might happen with "roll-up" screens. I am also a firm believer in simplicity. The less time you spend dealing with hardware, the more time you have to focus on the lesson. It is an excellent dual-role solution as well as an inexpensive alternate for costly smart-whiteboards that most districts cannot afford to buy in bulk.
With all the great deals out there, you don't have to break your budget for the right look. The solutions are vast and you'll be happy with the results.
has 18 years experience in the electronic technologies industry and is the Marketing Manager for Elite Screens Inc. In addition to being an industry product reviewer and commentator, he has published numerous articles regarding audio visual performance and big screen installation.