Benq lh820st projector position?

[victmor]

New member here. I am having trouble trying to figure out exactly where to mount the projector and I am hoping someone with experience or knowledge can help me out with this. In the photo you can see I have different levels of ceiling heights. The white ceiling is almost exactly 9' tall, but where the black beam comes down it is only 89" and the edge of it comes out 59" from the screen, so it's basically a 5' deep enclosure. I was hoping to have the top image of my screen to be as close to 89" as possible so I can take advantage of the full 10' wide screen in the 4:3 aspect ratio. The issue I am having is the vertical offset for the lh820st is going to be 9" with the projector mounted 79" from the screen. So I think if I mount it 9" above the top edge the top edge of the enclosure which comes out 5' it will obstruct the image. In which case I reached out to Carls and they said to mount it so the center of the lens sits just below the top of the enclosure and tilt it up and then adjust with keystone correction. I tried doing this with a ladder setup and I was having all kinds of trouble as it wasn't very stable and I didn't have anyone there to help me out so I wasn't able to get a good idea of how it would work out, plus the pc I was using was super old and I don't think it was displaying the correct resolution so that could have been part of the problem (I will be getting a gaming pc soon). So my question is 1. Will mounting just below the enclosure and tilting it up work? and 2. I'd like to mount is as far off center as possible. Is there any way to figure how many inches off to the right I can mount it without having to just experiment with it? When I was using the ladder it didn't seem like it would let me set it as far off center as I would like, but again I wasn't really able to fine tune it.

[irfan]

While you will lose some picture quality with a tilt + keystone it’s a solution I also have to resort to. The best way is really just playing with the positioning. I’ve found calculators get you close but you need to refine the position manually.

[ProjectSim]

Re Calculators, I found the same. Spent months during my build with anxiety about the Benq projector calculations as I was within 40mm (1 1/2 inches) of a bulkhead and still had to fit power/display port cables within that gap. Was literally dreaming the maths over many nights of sleep. Turns out the calculator was out by several inches, in the bad direction, and I had to totally change up my mounting plans at the last minute when the projector arrived (LK936ST). Lesson is to calculate over and over, yet add in a buffer.