Originally Posted by joechuan
Thank you very much for your suggestion!
Where do you like to sit in a movie theater?
THX calls for viewing to be about 1.5x the screen width, or vice-versa, your screen width is .66x your viewing distance.
So, from 12' that's a 8' wide screen which is about 110" diagonal.
What's that mean for you?
That means that if you like sitting DEAD CENTER in your typical movie theater, then a 110" diagonal screen, from 12' away, will recreate that effect almost exactly.
But, some people like the screen to be a bit bigger, so they sit closer.
That's fine - there is truly nothing wrong with that other than the reality that you may see some pixel structure from the projector at that distance. I certainly have that issue when I go to a digital movie theater, but I accept it because I like the larger image.
So, I would go to at least 120" if that's the case, and nothing wrong with 130" either from that distance.
Now, depending on your timing and setup, you could actually fire the projector up, hook up a Blu-ray player to it and just watch a movie on a white wall with a 120" and a 130" diagonal and see which version you prefer from a 12'-13' viewing distance. That's truly the best way to do things always IMO as it gives you something very personalized to your specific tastes. You may find you want something closer to 110" or even a bit bigger.
The Sony 30ES has lens shift which means that you should have no issue placing it 77" above the floor. Generally, you measure DOWN from the ceiling, not up from the floor when ceiling mounting. It is much easier to measure that way... usually.