Multiple projectors for image magnification reduce costs and add flexibility.
By George Tsintzouras
Engaging and inspiring today’s congregations is increasingly difficult in a world saturated with corporate and secular images. The solution for many churches is to make each service more creative and interactive — specifically, to use large-screen projection to support the message each week. Bright and colorful images large enough to be seen from every seat serve to capture and hold the congregation’s attention, allowing the essential messages to be easily delivered and understood.
However, a single projector and screen may not be sufficient to meet this goal, especially in larger buildings and auditoriums. There is a limit to how large a screen a single projector of reasonable size and cost can properly illuminate.
The preferred solution is a multi-projector system, with a large, main screen displaying one image/message and possibly one or more, smaller satellite images on physically separate screens. The large, main image can be constructed of smaller, blended images, one from each projector in an array, with the edges of each image blended into the overlapping edges of adjacent images to form one seamless, wide aspect, display.
When choosing a projector, there are several key considerations. One factor is built-in support for warping and blending of the projected image. This is critical for combining images in either a tiled or stacked configuration, since each projector will typically be aimed at the screen from a slightly different angle.
Tiled array problems
The next important consideration, particularly for a tiled array, is the projector’s illumination system. It may be tempting to use lower-cost, commodity projectors with a high-gain screen to compensate for their lower typical light output.
However, the tiled nature of the composite image will be immediately obvious to any viewer not directly in front of the screen’s center. Low-gain screens are necessary to avoid this, which requires projectors with higher light output.
Another valuable feature, which makes setting up and maintaining a multi-projector system easier, particularly if it is necessary to physically move it to a new location, is an automatic blending and stacking system. This option, available for certain projectors equipped with the aforementioned image warping and blending functionality, requires very little training to operate and can completely automate the process of stacking and edge blending, saving time and resources.
Don’t compromise the image
There is also the option to create the images in stacked configurations, with each projector displaying the same image on the same screen, each adding its light to the total or providing redundancy to ensure the service continues if a projector fails. As well, a multi-lamp projector provides additional built-in redundancy (if a lamp fails) and ensures that the show goes on and the overall presentation is not compromised.
In today’s tough economic times, cost of ownership is likely the most important factor in the purchase of a projection system. Here too, careful selection pays dividends. The optical efficiency of the projector is likely the largest contributor.
The cost of replacement lamps is also a factor; the small lamps used in multi-lamp projectors usually last longer, provide redundancy and cost less to replace than the larger lamps used in single-lamp projectors to achieve the same light output. Air filters, which typically must be replaced regularly, are another ongoing expense; a projector that can operate without them provides an obvious advantage.
An effective church projection system, regardless of its size, must be bright, flexible, reliable, meet the needs of the church leaders and congregation, and all fit within a defined budget.
George Tsintzouras is director of product management, business products for Christie Digital Systems USA Inc., Cypress, CA. [www.christiedigital.com]