hch

Speed, I'm not the ultimate authority, but I did set up my own projector system. The calculator should give you a good idea of the size of the area that will be lighted by the projector at a given distance. Whether you are viewing an image on the entire lighted area depends on aspect ratio, zoom, etc. A projector will have some lens zoom/focus adjustability to allow for perfecting a "pretty close" install. The gain of 1 on the screen means it should be basically neutral for reflecting light from the projector. A higher than 1 gain will reflect more light giving a brighter image, but usually at the cost of viewing angle. A lower than 1 gain will reflect less light but give deeper blacks and a higher constrast ratio. More or less. I use a screen with a gain of 1 and the low bulb setting. As I'm sure you know, another must for a projector setup is good ambient light control. If you have too much ambient light, the screen gain of 1 and low bulb mode may not work well. Good luck!!!