I receive numerous emails from churches asking about Video Projection. Listed below is one such church that is looking to upgrade their projector. What follows are a few of their questions. My responses are directed not only to them, but also to you, the reader.
Read on to follow this real-world example. - Anthony D. Coppedge, CTS, CAVSP
CHURCH
"...The projector needs to be at the back of the sanctuary, which is about 72 ft from the screen. Our current projector isn't bright enough to see unless all the windows are closed and the lights are turned off. So we are in the market from a new projector."
Anthony D. Coppedge
OK, first question: Why does it need to be at the back of the sanctuary? Sometimes there isn't a way to get it closer. Yet many times, it's an assumed place to put the projector - with no other reasoning.
In order to install a projector a long distance from the screen a long-throw lens will be required. Just like a camera needs long ‘zoom' lenses to see objects far away, the projector needs a longthrow lens to ‘shoot' the image that far away without filling up the entire wall.
Here's the first fact: Nearly all long-throw lenses allow less light to leave the projector because of the increased F-stop of the lens. There are very few exceptions to this, and those that do are very, very expensive. So that "really bright projector" may lose up to 50% of its brightness with a poor quality long-throw lens.
Therefore, by using 'less glass' (shorter throw distance lenses), you will have more light (lumen)at the screen. And an easy way to do this is to physically get that projector closer to the screen.
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Experiencing Worship, The Study