Originally Posted by PerpetualEnigma
I recently purchased a house and would like to upgrade from my 55-inch LED to a 120-inch projector screen in my living room which has ambient light from windows and where I would like to be able to watch shows/movies or play games during the day without turning off all the lights, such as in the open kitchen behind the sofa. I will attach pictures of the space below, you can see that my choices of projector are limited due to the location of the ceiling light/fan such that I believe I am restricted to a short throw projector, my current choice being the BenQ W1080ST (2000 lumens) which I would ceiling mount on the recessed ceiling between the fan and the wall. I do plan to install blinds on the two side windows to counter most of the outdoor ambient light. I am currently looking at the 120-inch Elite Screens CineGrey 1.0 gain screen, I had to eliminate the 1.5 gain CineGrey 5D as an option due to the short throw ratio of the W1080ST.
My proposed setup is:
BenQ W1080ST (2000 lumens) mounted about 6 ft from wall
120-inch Elite Screens CineGrey 1.0 gain
Approximately 45 lumens per square foot
Sofa at 13 ft viewing distance, easily significantly changed
8-ft ceilings, 9-ft where it's recessed
Movies, shows and gaming
Speakers moved out to beneath leaves of decorative trees
The bulb above the back wall intentionally dead
The question is will this be bright enough for moderate ambient light?
Otherwise is there a reasonably priced brighter short throw projector option or higher gain grey screen that isn't as limited in viewing angle and hotspotting for short throw?
Lastly, if I dropped down to a 100-inch Cinegrey 1.0 with approximately 60 lumens per square foot would it be bright enough in ambient light?
I would prefer not to remove the ceiling light/fan for this project.
One additional question for anyone with the W1080ST projector is how low will I have to mount it on the ceiling, as in how far up/down will it project the top of the image from where the lens is mounted?
The projector you plan on using has lots of light output. (1600 lumens on dynamic mode, 1200 lumens in Standard and Cinema modes) The problem i see is the screen you're planning to use. The big problem with a short throw projector for a home theater type use is the sharp angle the light is hitting the screen. At such a sharp angle, light is scattering all over the place. Your light walls will reflect the scattered light, wash out your screen, and destroy your contrast.
A high gain white screen (1.3 to 1.5) will help to focus the light more into the screen. You will have to learn to live with some sparkling.
An angular reflective or retro-reflective screen won't help you because the the short throw will give you severe hotspotting. (Like having a strong flashlight shining in the middle of the screen all the time)
A negative gain grey screen (Yes. The Elite Cinegrey 1.0 is a negative gain grey screen just like all the other regular grey screens) will help to prevent a lot of the light scatter (thus preserving some of your contrast) but requires more light output from your projector. Initially, Standard and Cinema modes will work fine. Over the lifetime of the bulb, the light output will drop until you find yourself having to stay in Dynamic mode most of the time.
Of the three choices I described, I think your best choice would be to use a white screen with a good amount of gain (1.3) and to treat the wall around the screen with dark material. Da-lite HD Progressive 1.3, Stewart Cima Neve 1.1, and Stewart Studiotek 130 would be my choices.
If you really want to go the angular or retro-reflective route, use a projector with a good amount of throw.