Selecting A Projection Screeen

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“YOU CAN’T PUT THAT THERE!”
The meeting with your church planning committee ends and this was the emphatic response to the result of hours spent developing projection plans. Jesus doesn’t need committees or video projection systems, but both are assets to reach people effectively. Selecting a screen that will suit your needs and still be aesthetically acceptable is sometimes difficult. Don’t give up! The solution may be just around the corner.

KNOW WHAT’S AVAILABLE
Before talking to your church about a projection system, do some research and get some professional advice. Good manufacturers are continually coming out with new products. In some cases, a manufacturer may have a local sales representative that will assist you to find the right product for your needs as well as a reputable installer.

FOUR STEPS TO A HAPPY CONGREGATION
Many churches don’t want the look of their worship center to change and others are open to anything that will work. Creating a balance of what will work and what will look good requires creativity, understanding and patience.

1. Select the type of screen.
If your church is narrow and deep, with adequate ceiling height, a center screen will probably provide the best viewing area and keep the focus toward the pulpit. If your church is wider than deep, and more fan-shaped, you may need two side screens for everyone to see well. Next, choose between having the screen remain stationary and always visible, or retractable and hidden when not in use. If your church prefers the screen not be seen when it isn’t needed, your best solution is to install a motorized front projection screen. If you can leave the screen in place, permanent wall screens can easily be mounted on the wall or in a wall opening. With so many shapes of churches, sometimes it is difficult to serve all the people with one or even two screens. It’s not uncommon to place smaller screens or television monitors in the worship center to enhance viewing.

Choosing between front and rear projection screen types is usually easy and your choice of motorized or stationary screen types may have narrowed the choices for you. Rear projection screens require a dedicated room behind the screen for placing the projector the proper distance from the screen. A mirror system can also be installed to shorten the distance needed from the projector to the screen in order to get your required image size.

If you have the luxury of using either front or rear projection, you might want to consider rear projection first. Rear projection screen material produces a higher quality image because the design of the material allows for less color bleeding and a higher resolution. Rear projection screens aren’t affected by ambient light as much as front projection screens because the ambient light transmits through the material rather than reflecting from it.

2. Select your projection format.
Most churches are using NTSC video format but some have embarked into HDTV. A few manufacturers even have motorized screens that will convert from one format to another by masking the screen with black material with the touch of a button. Select the format that will serve your church’s needs and use this in the calculations that follow. Here are the most common formats:

projectionscreen

3. Select the size of screen.
In order to be sure that your most distant viewer and closest viewer are both reading the projected text well and comfortably, you need to measure the distance from the screen to these two positions in the worship center.

Take the distance from the screen to the farthest viewer and divide it by eight to get the minimum screen height to serve this viewer. Next, take the distance from the screen to the closest viewer and divide it by 1.5. This gives you the maximum-comfort screen width for this viewer. To find the maximum-comfort screen height, divide it by the screen’s aspect ratio. Compare these two numbers and obtain a screen size that will serve the most people (in comfort).

In past years, experts calculated the width of a screen. This was fine for video formats but as other formats are used, it is safer to calculate the height. The only thing that changes with wider formats is how many text characters you can put on one line. The height of the character is what you want to make legible to the distant viewers. Therefore, experts are now calculating for screen height rather than width.

4. Choose Your Screen Surface.
There is very little choice in rear projection materials, but front projection materials are available in a wide variety of compositions. The two most commonly discussed factors in choosing a front projection screen material are gain and viewing angle. Rather than discuss the numerous types of screen materials, let’s look at what would narrow your choices.

Gain, in simple terms, is the reflectivity of a material. A device called a goniophotometer is used by manufacturers, both in the lighting and screen industries, to measure the directional light distribution characteristics of their products. What gain means to the church is how bright the image appears on the screen. Projecting an image on a painted wall results in very little light being reflected back to the audience. A projector would appear much brighter on a manufactured screen surface.

Viewing angle of a screen is determined by the structure of the screen material. Different types of surfaces will reflect light in different ways. The viewing angle of a screen material, however, is almost directly proportional to the gain. With the higher gain of a screen, comes a smaller viewing angle. The viewing angle is a number of degrees from the center axis of the screen where the projected image appears the brightest. When someone refers to a viewing cone, they are considering the total angle for both directions from the center axis. Find your seating angle by measuring the angle from the center axis of the screen to the seat farthest to the side. Then choose the screen with the highest gain available and a viewing angle that is equal or greater than your seating angle.

HOW LOW CAN YOU GO?
Making your projection screen so that it is comfortable for viewers is a key to having the new system accepted by the church. When possible, mount your screen so that the bottom of the screen is no lower than 6.5′ from the audience floor. When seated, the average height needed to see above a persons head is around 48 inches. However, almost every church will be standing to sing at some point during the service. At this time, everyone needs to be able to see over people who are standing. You may be able to mount the screen lower or higher depending on the grade or level of the seating.

Most manufacturers can add extra screen material, white material or black material to a screen’s length to lower the projection area down to a comfortable viewing position. This material is ordered as “extra drop” and it is usually recommended to use black so that the edge of the projected image is bordered or hidden. Using black creates a good contrast between the edge and the projected image. It will also hide minor keystoning caused by the projector.

For a more detailed look at selecting a screen, attend one of the Inspiration conferences or visit the Projection Solutions website at http://www.projectionsolutions.com for detailed information. Check this and other technology magazines for new product releases. Find value-added resellers who send out regular newsletters electronically or in print. Spend time researching your screen options and find the right solution.