The key to selecting the right video projector for your church is combining detailed preparation with a thorough product evaluation. How Bright is Bright Enough?Light output. As projection lamps age, light output diminishes. Most manufacturers deem that the useful life of a lamp ends when the lamp reaches 50 percent of its "as new" performance. Therefore, it might be wise to consider only projectors that meet your minimum brightness requirements when the lamp reaches its 50 percent output level. This means you would be starting with a projector that produces more light than necessary when the lamp is new. A projector that features an adjustable lamp power supply is the ideal choice. Maximum light and usable light. Maximum projector light output is the maximum light a projector is capable of producing. Usable light output is the amount of light a projector produces through a properly set up source. Usable light output is what matters for an application, and is therefore the important criteria for selecting a projector. Power StrugglesControl the voltage. Projectors have an internal power supply that converts the AC power from the facility (the mains power) to power needed for the lamp and internal electronics. The lamp and internal electronics require a tightly controlled voltage and current from the internal power supply. Any upsets in mains power can interrupt the operation of the internal power supply and place a considerable amount of stress on the lamp, the power supply, and other electronic components of the projector. Preventive measures. Make sure each projector has its own dedicated circuit to guard against dips in power. Be prepared for power spikes, inductive hum, and brownout conditions. To isolate the projector from these influences, use an online Universal Power Supply. A Spotlight on LampsXenon or metal halide? The vast majority of projectors use either xenon or metal halide lamp systems. Xenon lamps produce a color spectrum very close to that of daylight, enabling the projector to produce accurate colors. Xenon lamps also produce a stable spectral output, assuring consistency in the color performance as the lamp ages. These projectors are excellent choices for multi-projector venues and array applications. Metal halide lamps are relatively inexpensive, long lasting, and very efficient in producing brightness. The small size of these lamps enables projectors to be comparably small, lightweight, and power efficient. Metal halide is a good choice for high-use applications where long-term maintenance costs are a concern. However, metal halide lamps don't perform as well as xenon lamps with respect to spectral output or native white point. A Color-full PerformanceNative color. Native color, also referred to as "color temperature" or the "white point," is the color point of the projector before any user adjustments are applied. Projectors with an off-target native color point require significant adjustment, which in turn affects other performance aspects. Never employ a projector without first knowing its native white point performance, which can be defined by using a CIE 1931 chromaticity chart. The right mix. A projector creates color by internally generating red, green, and blue light energy and mixing them together to form the desired color. The bulbs and filters cannot produce pure colors that would be plotted on the very edges of the chromaticity chart. As a result, a projector will have a defined "color space" within the chart defined by a triangle of three specific points. These three points reflect the projector's limitations in creating "pure" red, green, and blue signals. Fill Factor, Lenses, and UniformityFill factor. Fill factor is the percentage of the projected image that contains information content as opposed to dead space between pixels. A higher fill factor means less dead space. Projectors with a combination of high resolution and a high fill factor will display smooth, film-like images. Projectors with a low fill factor will appear over-pixilated. The result can resemble looking at an image through a window screen. Lenses. Pay special attention to center-to-corner pixel focus and flare, magnification errors, light output efficiency, and brightness uniformity at every point on the screen. Conduct your projector evaluations using the same lens type that you will purchase with the projector. Uniformity. Determine whether a projector has "hot spots" or "holes" in the image. From center to corner, the projected image should be uniformly bright and smooth, with no areas that are brighter or dimmer than the rest of the image. The ability to produce a uniform image, called "flat field" illumination, gives a better visual appearance. This is always beneficial, but especially on large screens or when several projected images are tiled or edge-matched. Uniformity of illumination also creates uniform color and color balance across the screen. —Eric Lardner and Chris Coryell; Copyright © 2004 Christianity Today International. Originally appeared in Your Church. Discuss1. How well do we understand the specifications of our current projector? How well is it now performing? 2. What steps have we taken to avoid "spikes" and other potentially dangerous power fluctuations to the projector? 3. How do we evaluate the performance of our current projector? Who has the responsibility to make sure it is performing at its best?    Church Website Essentials Helpful advice for improving the church's new front door--the website.  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