Once you’ve decided on the location and type of projection screen that will best fit your church’s needs, the next item you need to be concerned with is size. The screen must be large enough to allow song lyrics and other information to be easily visible to everyone in the sanctuary.
There are several factors in sizing your projection screen: the size and layout of the room; the media to be projected; audience location in relation to the screen; and projection format must all be considered. These factors can for the most part be boiled down to two main issues: dimensions of the audience area, and the projection format to be used. In some cases, these two questions lead to the same conclusion; in others they don’t, and compromises have to be made.
The first thing to figure out is the screen height, that is, the size of the viewing surface from top to bottom. If you plan to be showing standard video (3:4) entertainment, screen height should be at least one-sixth the distance from the screen to the furthest seat; for charts and type, such as hymn lyrics or scripture readings, use one-fourth as a general guide; for complex graphics, use one-half. For HDTV (9:16) projection – the direction video is heading – screen height should equal or exceed one-third the distance from the screen to the center of the house.
Screen width is generally determined by the height of the screen, and the projection format to be used. To figure out what the screen width will be, use the formulas found in the “Screen Size Formulas” chart on the previous page.
The bottom of the screen should be approximately 40-48″ above the floor in a room with a level floor and several rows of seats. In sanctuaries with sloped floors, or small rooms with only one or two rows, the bottom of the screen should usually be 24-36″ above the floor. Evaluate any barriers and try to make sure that the lower part of the screen will be visible from all seats. If a roller-operated screen is installed in a room with a particularly high ceiling, extra material at the top of the screen may be required to position the screen at a comfortable viewing level. If possible, move around the room during a service, try several seats, and look for obstacles. Watch for the places where people stand in the front of the room.
Once you know roughly how big the screen needs to be based on the audience area, that size may be modified based on the projection equipment you’ll be using. If the screen will only be used with one type of projector (NTSC video, for example), determining exact screen dimensions is relatively simple. Projection formats are expressed in terms of aspect ratio, which is the relationship of the height of the projected image to its width.
Let’s say you’ve determined the back row will be 60 feet from the screen. While there may be some charts and other data projected, the main use will be to show lyrics. That means the screen height should be one-fourth the distance from the furthest seat to the screen. Since the back row is 60 feet away, now you know the screen height will be roughly 15 feet, or 180 inches. If the video format is 3:4, the screen width will be about 240 inches, with a diagonal measurement of about 300 inches.