Projector Help

[envision]

I am a bit confused with the projector central calculation website. I am looking at the popular Optoma GT1080 and BenQ HT2150ST. I plan on getting a 9 ft x 9 ft impact screen that will be mounted about a foot from the back white wall in the picture. The white portion of the ceiling is roughly 8'6" tall and the raised center section (so I can swing my driver) is roughly 10'6" tall. I plan on ceiling mounting the projector about 8 ft from the screen with a 4:3 ratio, hanging down from the raised center section, and directly above where I will be swinging my clubs. Where I am confused is when I do the calculation on a 9 ft x 9 ft screen, I get a diagonal of roughly 12'9". If I put the diagonal measurement in the calculator, it seems I should go with the Optoma. My concern with the Optoma is the offset. Any help would be much appreciated.

[vrpunk]

The Optoma has no zoom so be precise with its location from screen, use an adjustable ceiling pole mount to get your desired height from the ceiling they come in various sizes, also opt for the OptomaGT1080Darbee version for improved picture quality.
The offset is correct so it will be 15" above the top of your image so use the extension pole to get this precise from your ceiling, check the extension poles min / max width you can get small and large variants, the 0.49 throw ratio is great for no shadow casting.

[wbond]

With the optoma, if you fill the entire 9' width, the image would be 6'9" tall and the top of the image would start 13" below the center of the lens. The projector would be mounted 6' from the screen. If you go with the Benq at the same image width and height, the top of the image would start 2" below the center of the lens and the projector would be mounted 9'1" from the screen. Hope this helps, not sure what the question was or if i answered it.

[envision]

vrpunk - Not knowing exactly how the offset works, if I mounted the Optoma GT1080 recessed up in the raised center section so that the lens was above the bottom of the raised center section, would the image project below the bottom of the raised center section and those the image would project on the back wall near the top rather than 15" down? I tried to draw this scenario out on the picture below.

[vrpunk]

That looks exactly right, where centre of lens is 15" above the top of your image. The Optoma manual will give you the dimensions as well they do state 116% +- 5% offset so you have to cater for the lens centre being between 11% to 21% above the image, hence adjustable pole!

[wbond]

Probably depends upon how deep that section is and if you want the image to start at the floor or near the top of the screen. The most you will get at 4:3 with a 9' screen is going to be an image that's 6'9" tall. With the recess, i'm thinking you would need it to start at the floor. The center of the projector lens would be mounted about 8' off the floor.

[envision]

Both of you were extremely helpful in helping me understand the calculations. Much appreciated.

[envision]

I ended up ordering the Optoma GT1080 Darbee! Can't wait for it to get here! Now back to saving money for the next purchase.