Screen sizing - conflicting advice

I'm getting some conflicting advice from " the experts' and am soliciting Agon advice. I've purchased a used Digital Projection 3 Chip DLP Lightning 15sx (MSRP >$110,000)for a little bit more than I can buy a Seleco HT 300 plus for!

It is an amazing machine to say the least - 12,000 ansi lumens (No kidding)! Fortunately you can adjust light output down. In talking with Stewart and DP, they both agree a GreyHawk negative gain screen is necessary, however, size is the issue.

My theater is 20'Long x 16' Wide and 8' High. I want to have 2 rows of seating and use a 16x9 screen format. The projector will be mounted behind the rear wall of the theater.

Stewart says first row of seating should be roughly 5 times screen height for 480p output. On a 16x9 120" diagonal screen which has a 53" screen height and 96" width, that would put the first row at ~22'.

DP says 1.5 times screen width is sufficient, which would put the first row at 12'. DP says that you should get a s much width as possible because it is screen height that causes fatigue, not width. They feel that more than 80% of the action is in the middle of the screen and the sides are more filler than anything else.

I'm sure I'm missing something here. Can you help?

There are some real home theater experts at
As a salesman in the high end for 15 years, I have never heard of 1.5x screen height; and height being the cause of fatigue. I have a Stewart 133" hd ratio screen in one of our demo rooms and 12' is too close! But 22' seems too far. Our seating for 2 rows is 16-17'for 1st row. This gives me a great big picture, clear and crisp, without my eyes shifting giving me fatigue. I have watched over 4000 hours on this screen in the last 3 years I bet. Hope I helped. Mike