OHP distance from wall?

[Mr Baines]

hello, I am awaiting delivery of my new (and first) OHP. i already have my new (and first) LCD Panel.
What i want to know is how far from the screen/wall will I have to place the OHP to have the screen size I want?

Here are the specs so you will know what equipment i'm using:

LSK VD Magic II LCD panel which is 10" screen size.
3M 9700 OHP 4300 lumens.
The width of my room is 9 feet four inches.
So bearing all this in mind, what is the biggest screen size I can get from 9 feet four inches away?
Thanks.

BTW I know that there's a formula for working this out, its something like D = F ( S/A + 1 ) .But Im not clever enough to work this out for myself lol.

 

[Maximouse]

I just put one of my 10" panels on my OHP and placed the unit exactly 9'4" from my screen (screen to rear of OHP).

The result was a screen image of 74" diagonal.

Hope this helps.
Al