Light Output (light output)

It measures the amount of light produced by a front projector. This is expressed in "lumens" or "ANSI lumens." A larger number, the greater light output.  Light output varies depending on mode (color and white light output). Advanced, high-speed auto iris function adjusts light output up to 120 times per second. The ANSI contrast ratio is the result of dividing the average light output of the white rectangles by the average light output of the black squares.

The question that logically follows is, "how much stray light is too much?" A normal home theater projector usually has a brightness rating somewhere in the range of 800-1500 lumens. Given a projector with that kind of light output, the rule of thumb would be that if a room has enough light to read in, it is probably too bright for a standard home theater front projector. You don't need to have the room perfectly dark, although the darker the room, the better the image quality you will get out of your projector.

If your room just can't be configured to control ambient light, there are still a couple of options left if you are dead set on using a front. Modern projectors is the high light output. This means that in practical terms, virtually any screen will do, even a white wall can give good results in the right lighting conditions.